Project SV OU - Victim of the Week (Week 48: Assault Vest Hisuian Samurott)

[SunCooled]

Assuming this is the same as previous VotWs:
Check:
Counter:

 

[Milo]

Congratulations to Lectrys for winning our first week of Victim of the Week! Our next Victim, will be our winner!


Chi-Yu @ Choice Specs
Ability: Beads of Ruin
Tera Type: Fire / Dark
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature
IVs: 0 Atk
- Flamethrower
- Fire Blast
- Dark Pulse
- Overheat​

Chi-Yu has semmented itself as a potent wallbreaker with the ability to run Choice Specs, Choice Scarf and Nasty Plot sets. Whilst lacking coverage, Tera Blast gives it an edge when using a typing that isn't already one of its own. However, for this Choice Specs set, Fire and Dark Teras are more preferred as they give a big STAB boost alongside it's high SpA.

How will you punish this Victim? Submissions end Friday!

 

[Giyu]

Blissey (F) @ Heavy-Duty Boots
Ability: Natural Cure
Tera Type: Normal
EVs: 252 HP / 252 Def / 4 SpD
Bold Nature
IVs: 0 Atk
- Seismic Toss
- Soft-Boiled
- Stealth Rock
- Thunder Wave

252 SpA Choice Specs Adaptability Chi-Yu Overheat vs. 252 HP / 4 SpD Blissey: 336-396 (47 - 55.4%) -- 74.2% chance to 2HKO
eats

 

[Mugenman88]

Submitting SpD Tyranitar as a Check



Tyranitar @ Leftovers
Ability: Sand Stream
Tera Type: Rock
EVs: 252 HP / 4 Atk / 252 SpD
Careful Nature
- Rock Slide
- Earthquake
- Thunder Wave
- Stealth Rock

Pretty simple, this thing is ungodly fat in sand, Chi-Yu's only real way to 2HKO this thing is to crit on the 2nd Overheat and even that isn't a guaranteed 2HKO, and Tyranitar will always OHKO Chi-Yu with Rock Slide, even with tera Dark it's always a 2HKO.

(Beads of Ruin still isn't in the calc yet so I gave Chi-Yu base 197 SpA, If I've done this wrong let me know)
252 SpA Choice Specs Tera Fire Chi-Yu Overheat over 2 turns vs. 252 HP / 252+ SpD Tyranitar in Sand: 211-249 (52.2 - 61.6%) -- not a KO
252 SpA Choice Specs Tera Fire Chi-Yu Fire Blast vs. 252 HP / 252+ SpD Tyranitar in Sand: 119-140 (29.4 - 34.6%) -- 100% chance to 4HKO after Leftovers recovery
252 SpA Choice Specs Tera Dark Chi-Yu Dark Pulse vs. 252 HP / 252+ SpD Tyranitar in Sand: 86-102 (21.2 - 25.2%) -- possible 5HKO after Leftovers recovery


4 Atk Tyranitar Rock Slide vs. 0 HP / 0 Def Chi-Yu: 254-300 (101.1 - 119.5%) -- guaranteed OHKO
4 Atk Tyranitar Rock Slide vs. 0 HP / 0 Def Tera Dark Chi-Yu: 127-150 (50.5 - 59.7%) -- guaranteed 2HKO after sandstorm damage

 

[Lectrys]

Check


Iron Valiant @ Choice Band
Ability: Quark Drive
Tera Type: Fairy
EVs: 252 Atk / 4 SpD / 252 Spe
Jolly Nature
- Spirit Break
- Close Combat
- Knock Off
- Trick / Zen Headbutt

Thanks to outspeeding Specs Chi-Yu, CB Iron Valiant don't care 'bout no Fire Tera:

252 Atk Choice Band Iron Valiant Close Combat vs. 0 HP / 0 Def Tera Fire Chi-Yu: 354-417 (141 - 166.1%) -- guaranteed OHKO
(252 SpA Choice Specs Adaptability Beads of Ruin Chi-Yu Overheat vs. 0 HP / 4 SpD Iron Valiant: 656-772 (226.9 - 267.1%) -- guaranteed OHKO)

Watch this Iron Valiant set get checked by this thread's 1st Victim of the Week

 

[Vrin]

SpDef Roaring Moon is a counter to this set, even in the Sun.

Roaring Moon @ Heavy-Duty Boots
Ability: Protosynthesis
Tera Type: Water / Fairy / etc.
EVs: 40 HP / 248 SpD / 220 Spe
Careful Nature
- Crunch
- Earthquake
- Roost
- U-turn

Given spread hits 329 Speed, meaning it outspeeds non-Scarf Chi-Yu, and 330 SpDef, just enough to get the Special Defense boost from Protosynthesis in Sun. It can then Roost off the damage and scare Chi-Yu out with the threat of Earthquake, allowing it to grab momentum with a fast U-turn. If Chi-Yu Tera Darks or Grasses to lose the EQ weakness, then U-turn becomes super effective.

Calcs

0 Atk Roaring Moon Earthquake vs. 0 HP / 0 Def Chi-Yu: 230-272 (91.6 - 108.3%) -- 50% chance to OHKO

252 SpA Choice Specs Chi-Yu Overheat vs. 40 HP / 248+ SpD Roaring Moon: 156-184 (43.2 - 50.9%) -- 4.7% chance to 2HKO (0% factoring in the SpAtk drop)
252 SpA Choice Specs Chi-Yu Dark Pulse vs. 40 HP / 248+ SpD Roaring Moon: 96-114 (26.5 - 31.5%) -- guaranteed 4HKO

The below calcs are with the Protosynthesis boost:
252 SpA Choice Specs Chi-Yu Overheat vs. 40 HP / 248+ SpD Roaring Moon in Sun: 181-213 (50.1 - 59%) -- guaranteed 2HKO
252 SpA Choice Specs Chi-Yu Fire Blast vs. 40 HP / 248+ SpD Roaring Moon in Sun: 153-180 (42.3 - 49.8%) -- guaranteed 3HKO
Note that Roaring Moon DOES drop to a Tera Fire Fire Blast in Sun after taking a regular Fire Blast, so you'll want to consider Roosting if your opponent hasn't Tera'd yet; if it does Tera Fire, then you can then either Roost stall out Sun or just threaten a kill with EQ.

As an added bonus, Scarf sets deal basically nothing and so would need to get VERY lucky to flinch you to death:
252 SpA Chi-Yu Dark Pulse vs. 40 HP / 248+ SpD Roaring Moon: 64-76 (17.7 - 21%) -- possible 5HKO

Non-SpDef sets with Roost (e.g. Roost DD 2 attacks) also act as fairly reliable switchins, though can take a lot from Specs in the Sun. Sets without Roost (e.g. Choice Band, DD 3 attacks) can switch in once or twice.

Naturally, because Terastallize is in the tier, it doesn't counter absolutely all possible sets — Chi-Yu can blow it out with an unconventional Tera choice like Fairy or Fighting — but these are uncommon. Roaring Moon is, unfortunately, annoyed by Burn (from Wisp or Lava Plume variants or just from random Flamethrower/Fire Blast hax), but the SpDef variant still counters even when burned and can still get momentum with fast U-turns, whereas more common DD sets are just completely crippled by Burn.

 

[1LDK]

CHECK


Sylveon @ Leftovers
Ability: Pixilate
Tera Type: Fire/Steel
EVs: 252 HP / 4 SpA / 252 SpD
Calm Nature
IVs: 0 Atk
- Hyper Voice
- Wish
- Protect
- Tera Blast/Shadow Ball


If Sylveon enters at the same time as Cheap-U, then She can lock him with protec and give entry to other things
If she enters on Chi Yu

4 SpA Pixilate Sylveon Hyper Voice vs. 0 HP / 4 SpD Chi-Yu: 109-129 (43.4 - 51.3%) -- 5.9% chance to 2HKO
252 SpA Choice Specs Chi-Yu Dark Pulse vs. 252 HP / 252+ SpD Sylveon: 80-95 (20.3 - 24.1%) -- possible 6HKO after Leftovers recovery

She needs to enter in a dark move, because she gets 2HKO with the fire attacks
Unless, you tera into fire


252 SpA Choice Specs Chi-Yu Flamethrower vs. 252 HP / 252+ SpD Tera Fire Sylveon: 90-107 (22.8 - 27.1%) -- possible 5HKO after Leftovers recovery
252 SpA Choice Specs Chi-Yu Fire Blast vs. 252 HP / 252+ SpD Tera Fire Sylveon: 111-131 (28.1 - 33.2%) -- 92.4% chance to 4HKO after Leftovers recovery
252 SpA Choice Specs Chi-Yu Dark Pulse vs. 252 HP / 252+ SpD Tera Fire Sylveon: 160-190 (40.6 - 48.2%) -- guaranteed 3HKO after Leftovers recovery


All this calcs are with Ruin thingy in mind, i hope i did the calcs right

 

[awyp]

Check:


Azumarill @ Assault Vest
Ability: Huge Power
Tera Type: Electric
EVs: 244 HP / 252 Atk / 4 Def / 4 SpD / 4 Spe
Adamant Nature
- Liquidation
- Play Rough
- Aqua Jet
- Ice Spinner

Calcs:

Chi-Yu (Fire Blast) vs Azumarill

252 SpA Choice Specs Chi-Yu Fire Blast vs. 244 HP / 4 SpD Assault Vest Azumarill: 147-173 (36.5 - 43%) -- guaranteed 3HKO

Chi-Yu (Dark Pulse) [Tera Dark] vs Azumarill

252 SpA Choice Specs Tera Dark Chi-Yu Fire Blast vs. 244 HP / 4 SpD Assault Vest Azumarill: 147-173 (36.5 - 43%) -- guaranteed 3HKO

This is probably more of a counter to be fair since it'll never 2HKO (Fire Blast or Dark Pulse with Tera Dark in play) but I don't know if entry hazard is in play or what not, so I'll say check. Thick Fat set with Assault Vest + 252 HP / 252 SpD could take hits better but I don't think it's actually viable IMHO.

Aqua Jet will 2HKO (If you decide to go with Tera Type Water (Which I won't include on the set), it'll OHKO. Liquidation will OHKO, but if you want to avoid Dark Pulse flinch, I would go with Aqua Jet.

 

[Joseph Gomes]

The above Clodsire calcs are wrong since they don't take Beads of Ruin into account


252 SpA Choice Specs Chi-Yu Flamethrower vs. 252 HP / 252+ SpD Clodsire affected by Beads of Ruin: 217-256 (46.7 - 55.1%) -- 14.1% chance to 2HKO after Leftovers recovery

 

[Bice]

Choice Scarf Rotom-Wash as a Check

Rotom-Wash @ Choice Scarf
Ability: Levitate
Tera Type: Ground
EVs: 252 HP / 4 Def / 252 Spe
Timid Nature
- Volt Switch
- Hydro Pump
- Trick
- Thunder Wave

Obviously can't come in safely (pretty much nothing can lol), especially not on Dark Pulse, but can at least survive one hit from the fish and outspeed it with Scarf to cripple it with Thunder Wave and/or dent (possibly kill) it with Hydro Pump. The KO is guaranteed if Chi-Yu gets hit by Stealth Rock, so rocks support is recommended. Even if Chi-Yu runs something like Tera Grass it's still not gonna appreciate getting paralyzed.
Because the Ruin abilities aren't on the calc yet, damage calcs were done in a manner that gave Rotom 188 Special Defense, which is roughly factoring in Beads of Ruin.

252 SpA Choice Specs Chi-Yu Overheat vs. 252 HP / 0 SpD Rotom-Wash: 205-242 (67.4 - 79.6%) -- guaranteed 2HKO
252 SpA Choice Specs Chi-Yu Dark Pulse vs. 252 HP / 0 SpD Rotom-Wash: 253-298 (83.2 - 98%) -- guaranteed 2HKO

0 SpA Rotom-Wash Hydro Pump vs. 0 HP / 4 SpD Chi-Yu: 212-252 (84.4 - 100.3%) -- guaranteed OHKO after Stealth Rock

 

[HydreigonTheChild]

Iron Valiant @ Booster Energy
Ability: Quark Drive
Tera Type: Dark
EVs: 252 Atk / 4 Def / 252 Spe
Jolly Nature
- Swords Dance
- Spirit Break
- Close Combat
- Knock Off

252 Atk Iron Valiant Close Combat vs. 0 HP / 0 Def Chi-Yu: 474-558 (188.8 - 222.3%) -- guaranteed OHKO
252 Atk Iron Valiant Close Combat vs. 0 HP / 0 Def Tera Fire Chi-Yu: 237-279 (94.4 - 111.1%) -- 62.5% chance to OHKO
+2 252 SpA Tera Fire Chi-Yu Dark Pulse vs. +1 0 HP / 4 SpD Iron Valiant: 67-79 (23.1 - 27.3%) -- 72.3% chance to 4HKO

its a check as you can switch in on dark stab in an emergency but overall you outspeed it and smack it with a cc and can even KO it if tera fire

 

[Z'rima]

Check


Clodsire @ Leftovers
Ability: Unaware
Tera Type: Water
EVs: 252 HP / 4 Atk / 252 SpD
Careful Nature
- Curse
- Recover
- Earthquake
- Megahorn

Clodsire is free to soak up Chi-Yu hits all day, and at most Chi-Yu 2HKOs, but Clodsire can easily heal up with Recover. +1 EQ OHKOs and a Megahorn has a 98.4% chance to 2HKO. In most cases Chi-Yu would click an attacking move while you go for Curse, Chi-Yu clicks another attacking move and you Recover, and then you EQ, or Megahorn in the case of Dark Tera Type. Water Tera Type is for to soak up Chi-Yu's hits further.

This set unfortunately doesn't take into account the fact that Unaware ignores opponents' stat drops. Overheat from specs Chi-Yu will always 2HKO, even after Water tera from Clod, and with Fire tera it has a good chance to OHKO. Water Absorb sets do a little better, but you still barely outheal Dark Pulse, and are likely to run up against a flinch.

Specs Chi-Yu is generally a nightmare for Clodsire to deal with

 

[Low-Key]

This set unfortunately doesn't take into account the fact that Unaware ignores opponents' stat drops. Overheat from specs Chi-Yu will always 2HKO, even after Water tera from Clod, and with Fire tera it has a good chance to OHKO. Water Absorb sets do a little better, but you still barely outheal Dark Pulse, and are likely to run up against a flinch.

Specs Chi-Yu is generally a nightmare for Clodsire to deal with

well that.... is unfortunate. Yeah I've practically removed Clodsire all together but I might be able to replace it soon. Sorry if I was a stupid man who'd forgot to take stuff into account.

 

[AnandOza]

Haha, this thread is doing the same Pokemon in the same order as https://www.smogon.com/forums/threads/sv-ou-lure-that-threat-week-3-annihilape-submissions.3712577/

 

[Lectrys]

Haha, this thread is doing the same Pokemon in the same order as https://www.smogon.com/forums/threads/sv-ou-lure-that-threat-week-3-annihilape-submissions.3712577/

It's probably not coincidence that both threads picked the current only resident of S tier in OU in Week 1 and the mon currently most requested for a ban from OU (arguably even regardless of Tera staying or getting nerfed/banned) in Week 2.

If this thread picks Annihilape the dangerous set-up sweeper (I'm personally convinced that the RestTalk set crushes stall but is weaker against offence, while typical Bulk Up sets are more well-rounded) in Week 3, the threads will look even more similar, but I can easily see this thread switching things up for the dangerous fast sniper pivot Dragapult, the bulky, versatile, and strong Great Tusk, the aggressive fast breaker-cleaner Chien-Pao, or the current Dragon Dance favourite Dragonite (among others) in Week 3.

 

[Milo]

Late Voting is up! Ends Tomorrow!

Blissey (F) @ Heavy-Duty Boots
Ability: Natural Cure
Tera Type: Normal
EVs: 252 HP / 252 Def / 4 SpD
Bold Nature
IVs: 0 Atk
- Seismic Toss
- Soft-Boiled
- Stealth Rock
- Thunder Wave

252 SpA Choice Specs Adaptability Chi-Yu Overheat vs. 252 HP / 4 SpD Blissey: 336-396 (47 - 55.4%) -- 74.2% chance to 2HKO
eats

Submitting SpD Tyranitar as a Check



Tyranitar @ Leftovers
Ability: Sand Stream
Tera Type: Rock
EVs: 252 HP / 4 Atk / 252 SpD
Careful Nature
- Rock Slide
- Earthquake
- Thunder Wave
- Stealth Rock

Pretty simple, this thing is ungodly fat in sand, Chi-Yu's only real way to 2HKO this thing is to crit on the 2nd Overheat and even that isn't a guaranteed 2HKO, and Tyranitar will always OHKO Chi-Yu with Rock Slide, even with tera Dark it's always a 2HKO.

(Beads of Ruin still isn't in the calc yet so I gave Chi-Yu base 197 SpA, If I've done this wrong let me know)
252 SpA Choice Specs Tera Fire Chi-Yu Overheat over 2 turns vs. 252 HP / 252+ SpD Tyranitar in Sand: 211-249 (52.2 - 61.6%) -- not a KO
252 SpA Choice Specs Tera Fire Chi-Yu Fire Blast vs. 252 HP / 252+ SpD Tyranitar in Sand: 119-140 (29.4 - 34.6%) -- 100% chance to 4HKO after Leftovers recovery
252 SpA Choice Specs Tera Dark Chi-Yu Dark Pulse vs. 252 HP / 252+ SpD Tyranitar in Sand: 86-102 (21.2 - 25.2%) -- possible 5HKO after Leftovers recovery


4 Atk Tyranitar Rock Slide vs. 0 HP / 0 Def Chi-Yu: 254-300 (101.1 - 119.5%) -- guaranteed OHKO
4 Atk Tyranitar Rock Slide vs. 0 HP / 0 Def Tera Dark Chi-Yu: 127-150 (50.5 - 59.7%) -- guaranteed 2HKO after sandstorm damage

Check


Iron Valiant @ Choice Band
Ability: Quark Drive
Tera Type: Fairy
EVs: 252 Atk / 4 SpD / 252 Spe
Jolly Nature
- Spirit Break
- Close Combat
- Knock Off
- Trick / Zen Headbutt

Thanks to outspeeding Specs Chi-Yu, CB Iron Valiant don't care 'bout no Fire Tera:

252 Atk Choice Band Iron Valiant Close Combat vs. 0 HP / 0 Def Tera Fire Chi-Yu: 354-417 (141 - 166.1%) -- guaranteed OHKO
(252 SpA Choice Specs Adaptability Beads of Ruin Chi-Yu Overheat vs. 0 HP / 4 SpD Iron Valiant: 656-772 (226.9 - 267.1%) -- guaranteed OHKO)

Watch this Iron Valiant set get checked by this thread's 1st Victim of the Week

SpDef Roaring Moon is a counter to this set, even in the Sun.

Roaring Moon @ Heavy-Duty Boots
Ability: Protosynthesis
Tera Type: Water / Fairy / etc.
EVs: 40 HP / 248 SpD / 220 Spe
Careful Nature
- Crunch
- Earthquake
- Roost
- U-turn

Given spread hits 329 Speed, meaning it outspeeds non-Scarf Chi-Yu, and 330 SpDef, just enough to get the Special Defense boost from Protosynthesis in Sun. It can then Roost off the damage and scare Chi-Yu out with the threat of Earthquake, allowing it to grab momentum with a fast U-turn. If Chi-Yu Tera Darks or Grasses to lose the EQ weakness, then U-turn becomes super effective.

Calcs

0 Atk Roaring Moon Earthquake vs. 0 HP / 0 Def Chi-Yu: 230-272 (91.6 - 108.3%) -- 50% chance to OHKO

252 SpA Choice Specs Chi-Yu Overheat vs. 40 HP / 248+ SpD Roaring Moon: 156-184 (43.2 - 50.9%) -- 4.7% chance to 2HKO (0% factoring in the SpAtk drop)
252 SpA Choice Specs Chi-Yu Dark Pulse vs. 40 HP / 248+ SpD Roaring Moon: 96-114 (26.5 - 31.5%) -- guaranteed 4HKO

The below calcs are with the Protosynthesis boost:
252 SpA Choice Specs Chi-Yu Overheat vs. 40 HP / 248+ SpD Roaring Moon in Sun: 181-213 (50.1 - 59%) -- guaranteed 2HKO
252 SpA Choice Specs Chi-Yu Fire Blast vs. 40 HP / 248+ SpD Roaring Moon in Sun: 153-180 (42.3 - 49.8%) -- guaranteed 3HKO
Note that Roaring Moon DOES drop to a Tera Fire Fire Blast in Sun after taking a regular Fire Blast, so you'll want to consider Roosting if your opponent hasn't Tera'd yet; if it does Tera Fire, then you can then either Roost stall out Sun or just threaten a kill with EQ.

As an added bonus, Scarf sets deal basically nothing and so would need to get VERY lucky to flinch you to death:
252 SpA Chi-Yu Dark Pulse vs. 40 HP / 248+ SpD Roaring Moon: 64-76 (17.7 - 21%) -- possible 5HKO

Non-SpDef sets with Roost (e.g. Roost DD 2 attacks) also act as fairly reliable switchins, though can take a lot from Specs in the Sun. Sets without Roost (e.g. Choice Band, DD 3 attacks) can switch in once or twice.

Naturally, because Terastallize is in the tier, it doesn't counter absolutely all possible sets — Chi-Yu can blow it out with an unconventional Tera choice like Fairy or Fighting — but these are uncommon. Roaring Moon is, unfortunately, annoyed by Burn (from Wisp or Lava Plume variants or just from random Flamethrower/Fire Blast hax), but the SpDef variant still counters even when burned and can still get momentum with fast U-turns, whereas more common DD sets are just completely crippled by Burn.

CHECK


Sylveon @ Leftovers
Ability: Pixilate
Tera Type: Fire/Steel
EVs: 252 HP / 4 SpA / 252 SpD
Calm Nature
IVs: 0 Atk
- Hyper Voice
- Wish
- Protect
- Tera Blast/Shadow Ball


If Sylveon enters at the same time as Cheap-U, then She can lock him with protec and give entry to other things
If she enters on Chi Yu

4 SpA Pixilate Sylveon Hyper Voice vs. 0 HP / 4 SpD Chi-Yu: 109-129 (43.4 - 51.3%) -- 5.9% chance to 2HKO
252 SpA Choice Specs Chi-Yu Dark Pulse vs. 252 HP / 252+ SpD Sylveon: 80-95 (20.3 - 24.1%) -- possible 6HKO after Leftovers recovery

She needs to enter in a dark move, because she gets 2HKO with the fire attacks
Unless, you tera into fire


252 SpA Choice Specs Chi-Yu Flamethrower vs. 252 HP / 252+ SpD Tera Fire Sylveon: 90-107 (22.8 - 27.1%) -- possible 5HKO after Leftovers recovery
252 SpA Choice Specs Chi-Yu Fire Blast vs. 252 HP / 252+ SpD Tera Fire Sylveon: 111-131 (28.1 - 33.2%) -- 92.4% chance to 4HKO after Leftovers recovery
252 SpA Choice Specs Chi-Yu Dark Pulse vs. 252 HP / 252+ SpD Tera Fire Sylveon: 160-190 (40.6 - 48.2%) -- guaranteed 3HKO after Leftovers recovery


All this calcs are with Ruin thingy in mind, i hope i did the calcs right

Check:


Azumarill @ Assault Vest
Ability: Huge Power
Tera Type: Electric
EVs: 244 HP / 252 Atk / 4 Def / 4 SpD / 4 Spe
Adamant Nature
- Liquidation
- Play Rough
- Aqua Jet
- Ice Spinner

Calcs:

Chi-Yu (Fire Blast) vs Azumarill

252 SpA Choice Specs Chi-Yu Fire Blast vs. 244 HP / 4 SpD Assault Vest Azumarill: 147-173 (36.5 - 43%) -- guaranteed 3HKO

Chi-Yu (Dark Pulse) [Tera Dark] vs Azumarill

252 SpA Choice Specs Tera Dark Chi-Yu Fire Blast vs. 244 HP / 4 SpD Assault Vest Azumarill: 147-173 (36.5 - 43%) -- guaranteed 3HKO

This is probably more of a counter to b

Choice Scarf Rotom-Wash as a Check
View attachment 479117
Rotom-Wash @ Choice Scarf
Ability: Levitate
Tera Type: Ground
EVs: 252 HP / 4 Def / 252 Spe
Timid Nature
- Volt Switch
- Hydro Pump
- Trick
- Thunder Wave

Obviously can't come in safely (pretty much nothing can lol), especially not on Dark Pulse, but can at least survive one hit from the fish and outspeed it with Scarf to cripple it with Thunder Wave and/or dent (possibly kill) it with Hydro Pump. The KO is guaranteed if Chi-Yu gets hit by Stealth Rock, so rocks support is recommended. Even if Chi-Yu runs something like Tera Grass it's still not gonna appreciate getting paralyzed.
Because the Ruin abilities aren't on the calc yet, damage calcs were done in a manner that gave Rotom 188 Special Defense, which is roughly factoring in Beads of Ruin.

252 SpA Choice Specs Chi-Yu Overheat vs. 252 HP / 0 SpD Rotom-Wash: 205-242 (67.4 - 79.6%) -- guaranteed 2HKO
252 SpA Choice Specs Chi-Yu Dark Pulse vs. 252 HP / 0 SpD Rotom-Wash: 253-298 (83.2 - 98%) -- guaranteed 2HKO

0 SpA Rotom-Wash Hydro Pump vs. 0 HP / 4 SpD Chi-Yu: 212-252 (84.4 - 100.3%) -- guaranteed OHKO after Stealth Rock

is in play or what not, so I'll say check. Thick Fat set with Assault Vest + 252 HP / 252 SpD could take hits better but I don't think it's actually viable IMHO.

Aqua Jet will 2HKO (If you decide to go with Tera Type Water (Which I won't include on the set), it'll OHKO. Liquidation will OHKO, but if you want to avoid Dark Pulse flinch, I would go with Aqua Jet.

Iron Valiant @ Booster Energy
Ability: Quark Drive
Tera Type: Dark
EVs: 252 Atk / 4 Def / 252 Spe
Jolly Nature
- Swords Dance
- Spirit Break
- Close Combat
- Knock Off

252 Atk Iron Valiant Close Combat vs. 0 HP / 0 Def Chi-Yu: 474-558 (188.8 - 222.3%) -- guaranteed OHKO
252 Atk Iron Valiant Close Combat vs. 0 HP / 0 Def Tera Fire Chi-Yu: 237-279 (94.4 - 111.1%) -- 62.5% chance to OHKO
+2 252 SpA Tera Fire Chi-Yu Dark Pulse vs. +1 0 HP / 4 SpD Iron Valiant: 67-79 (23.1 - 27.3%) -- 72.3% chance to 4HKO

its a check as you can switch in on dark stab in an emergency but overall you outspeed it and smack it with a cc and can even KO it if tera fire

 

[Mugenman88]

 

[Lectrys]

Pretty nastily, a lot if not all of those counters stop being counters and checks stop being checks the moment Chi-Yu goes Tera Fire. So, this is the most secure option left IMO:

 

[Low-Key]

Pretty nastily, a lot if not all of those counters stop being counters and checks stop being checks the moment Chi-Yu goes Tera Fire.

kind of agreed

 

[awyp]

Going with when it comes to this set specifically (Tera Type Fighting Tera Blast is a different story). These are all fantastic sets though.

 

[Giyu]

 

[1LDK]

i would love to self vote but lets be objective, ttar is the best check (when no tera is around)

 

[Bice]

pretty much same as above, this fish is stupid lol

 

[Joseph Gomes]

is the surely the only reliable check that doesn't care about Chi-Yu's held item (Scarf invalidates CB Iron Valiant), and tera fire/dark, or force to invest EV into Sp Def like Roaring Moon (which is a suboptimal set).

 

[Vastus]

I've played around with Ttar, and as much as I love the mon, SpDef sets are just too passive to be generally useful outside of checking murderfish from my experience. It is the safest Chi-Yu check though.