Adaptability: This Pokemon's same-type attack bonus (STAB) is 2 instead of 1.5.
Adaptability will always be a strong ability no matter the metagame, but for me it feels a little underwhelming. With 18 types in the game, the odds of getting one of two on your attacks is unlikely. It will almost always be more beneficial to chose a more reliable damage boost, such as Download or Intrepid Sword.
Air Lock/Cloud Nine: While this Pokemon is active, the effects of weather conditions are disabled.
Could be good if ladder is full of weather, but ultimately it is only good when weather comes into play. When it does come into play, it can be very good, ruining strategies such as Mega-Camerupt in Desolate Land.
Anger Shell: At 1/2 or less of this Pokemon's max HP: +1 Atk, Sp. Atk, Spe, and -1 Def, Sp. Def.
Feels like it would be a solid alternative to Berserk, with the added bonus of Atk and Spe, but the defense drops help to even it out.
Bad Dreams: Causes sleeping adjacent foes to lose 1/8 of their max HP at the end of each turn
Has a niche but isn't terrific. Very rewarding if you get the sleep though.
Bulletproof: Makes user immune to ballistic moves (Shadow Ball, Sludge Bomb, Focus Blast, etc)
Definitely on the more underused side, the immunity that bulletproof provides is very useful, stopping potentially fatal attacks, but it doesn't see too much usage because it's metronome battles, you never know when a ballistic attack is coming.
Chlorophyll: If Sunny Day is active, this Pokemon's speed is doubled
While speed is definitely useful in metronome battles, I certainly don't feel like it is strong enough to necessitate it on many teams. With the extremely high speed you will get under the sun, you become susceptible to losing to Perish Song. There are also stronger abilities to be using on sun teams, such as Cherrim's Flower Gift, or using Solar Power.
Clear Body/Full Metal Body/White Smoke: Prevents other Pokemon from lowering this Pokemon's stat stages
This is outclassed in most scenarios by Mirror Armor. The only scenario where you would use this instead is against Defiant/Competitive builds. Completely outclassed by dual grass + Flower Veil. Always use Full Metal Body due to it ignoring Mold Breaker type abilities.
Contrary: If this Pokemon has a stat stage raised it is lowered instead, and vice versa
Contrary is very much a double edged sword, as stat drops are no longer detrimental to your team, stat boosts are now bad. While it has seen some usage, it just doesn't feel consistent at all for me.
Dancer: After another Pokemon uses a dance move, this Pokemon uses the same move
This is funny and not terrible
Disguise: (Mimikyu only) The first hit it takes is blocked, and it takes 1/8 HP instead
While this ability is pretty solid, it is hindered by the fact that you have to use it with Mimikyu. While Mimikyu's ghost typing is useful for metronome battles, its low attacking stats and lack of resistances cause it to fall at 132 on the usage stats as of writing this.
Dragon's Maw/Transistor: This Pokemon's attacking stat is multiplied by 1.5 while using a Dragon/Electric-type attack
These abilities fall here for the same reason that Adaptability does, because it will only benefit the user every so often. When you get locked into Outrage with Dragon's Maw it will certainly seem powerful, but you have to remember that RNG is a big part of the game, and that these abilities can only help you so much.
Drizzle/Drought: On switch-in, this Pokemon summons Rain Dance/Sunny Day
While not completely useless, it is generally more beneficial to use the Primal weather abilities over Drizzle/Drought. The 5 turn limit will only do so much for you, and if you really want more turns you should just switch to primals, because using a weather rock is a waste of an item slot. The upside to these is that it doesn't completely eliminate water/fire type moves, it just weakens them, allowing you to get more Weakness Policy procs.
Effect Spore: 30% chance of poison/paralysis/sleep on others making contact with this Pokemon
This one has a chance to move up once I test it a little more since I haven't ever used it. On paper it seems alright, mainly if you can roll poison with any semblance of consistency. We'll see on this though.
Electric Surge: On switch-in, this Pokemon summons Electric Terrain
The pros of Electric Terrain are very nice, immunity to sleep, and boosted electric type attacks. However, like the weathers listed above, the 5 turn limit isn't enough to justify it, and running Terrain Extender feels like a waste of an item slot. I have used it myself, paired with a Galvanize Mega-Ampharos, so that any electric type attacks used in that 5 turn window hit like a brick wall.
Flame Body: 30% chance a Pokemon making contact with this Pokemon will be burned
Effect Spore but with some more consistency, this might move up as well.
Flower Gift: If user is Cherrim and Sunny Day is active, it and allies's Attack and Sp. Def are 1.5x
If any other Pokemon could use this ability I feel like it would be S tier, but since it is restricted to Cherrim, with some more than underwhelming 70/70/78 bulk, it falls here.
Galvanize: This Pokemon's Normal-Type attacks become Electric Type and have 1.2x power
I really wanted to put this higher, trust me. I just couldn't end up doing it because of ground types. Sure, the boost is very nice, but giving your opponents another potential immunity that they didn't already have doesn't completely justify it.
Hadron Engine: On switch-in, summons Electric Terrain. During Electric Terrain, Sp. Atk is 1.3333x.
Almost dropped this to C, but I feel like it can't be that bad, especially because you also have the off chance of someone rolling Electric Terrain during a battle, and pairing it with a Quark Drive or Galvanize mon can't be terrible.
Healer: 30% chance of curing an adjacent ally's status at the end of each turn
It's alright, but you might as well use abilities that prevent status altogether like Flower Veil
Hydration: This Pokemon has its status cured at the end of each turn if Rain Dance is active
Probably decent under Primordial sea
Ice Face: If Eiscue, the first physical hit it takes deals 0 damage. This effect is restored in hail
Similar deal to Mimikyu, where this ability would be much better if it could be used with a different Pokemon. However, AV Cosmoem made a team with Kee Berry Eiscue, so after the first physical hit you get a defense boost. However, it will just be better to run Dauntless Shield most of the time.
Innards Out: If this Pokemon is Koed with a move, that move's user loses an equal amount of HP
Recently popularized with Bonk's Innards Out Ring Target Chansey, Innards Out is a fun, yet very niche ability. Lots of times you can get the ideal 1v1 scenario, but then you will roll earthquake with Chansey's ally turn 1 and you lose instantly.
Infiltrator: Moves ignore substitutes and foe's Reflect/Light Screen/Safeguard/Mist/Aurora Veil
It alright. Has some potential but suffers from inconsistency.
Intimidate: This Pokemon lowers the attack of adjacent opponents by one stage.
Definitely has potential to be used in the metagame, however with the looming presence of Defiant and Competitive, it really just isn't super reliable. Some games you get your -1 attack, but others you just start by giving your opponent +1.
Levitate: This Pokemon is immune to Ground. Gravity/Ingrain/Smack Down/Iron Ball nullify it.
Don't get me wrong, levitate is good. However, its usage is only necessitated on Pokemon with a 4x ground weakness, such as Heatran, Rotom-Heat, Typhlosion, etc, which are not very useful. You also miss out on potential benefits like healing from grassy terrain, and status immunity from misty terrain.
Libero/Protean: This Pokemon's type changes to the type of the move it is using. Once per switch-in.
Basically you get Tera Normal on your Mega-Evolved Pokemon, could be nice with Mega-Heracross.
Magician: If this Pokemon has no item, it steals the item off a Pokemon it hits with an attack
Niche but can be good. Best if used with something like a Weakness Policy, which is the best consumable item, or with a terrain berry if you like using terrain. You can also opt for more consistency by running no item.
Neuroforce: This Pokemon's attacks that are super effective against the target do 1.25x damage
I thought about this one for a while. I have yet to see this be used, but on paper it looks really good, taking what is already good damage, and making it hit even harder. However, in a metagame where most Pokemon that are chosen are made to have minimal weaknesses, I think it is more worthwhile to be using Tinted Lens, as it is better to make your weak attacks stronger as opposed to making your strong attacks stronger.
No Guard: Every move used by or against this Pokemon will always hit
Everytime I roll an OHKO move I think "Man, it would've been nice if I was running No Guard right now" and then I run No Guard and never roll an OHKO move. Not the best because your opponents get the benefits without the effort.
Normalize: This Pokemon's moves are changed to be Normal-Type and have 1.2x power
This can be debatable as I see the benefits of Normalize, but the looming presence of ghost types like Dusclops, Dragapult, Mega-Sableye, and Mega-Gengar make it much worse in the long run.
Pastel Veil: This Pokemon and its allies cannot be poisoned. On switch-in, cures poisoned allies
I mean I guess it's alright. Definitely has consistency as opposed to shed skin or healer, but I don't think poison is that big of a deal.
Pickup: If this Pokemon has no item, it finds one used by an adjacent Pokemon this turn
Pretty fun to use with either dual Weakness Policy or some berries. I have noticed that this is a way to use a modified Harvest + Rowap/Jaboca berries. With this
team, once both Rowap Berries have been eaten, you will begin to pickup new Rowap berries. Not super consistent, but a cool loophole.
Poison Point: 30% chance a Pokemon making contact with this Pokemon will be poisoned
Pretty much the same as Poison Touch (see below). Honestly just take your pick.
Poison Touch: This Pokemon's contact moves have a 30% chance of poisoning
Not seen too often but could definitely be nice. This is the most consistent method of poisoning in the metagame, but I think that a big rise in usage here would also cause a big rise in usage for Pastel Veil/Healer/Shed Skin etc.
Power Spot: This Pokemon's allies have the power of their moves mulitplied by 1.3
If only this effected the user as well, this would be S tier 100%. Still pretty good, that buff is better than one would think.
Prankster: This Pokemon's status moves have priority raised by 1, but Dark types are immune.
Would be better in earlier gens which didn't have the dark type immunity, however with that it becomes very underused and underwhelming. Very good when no dark types are present, but then you run into double Mega-Sableye and you can't do anything.
Protosynthesis/Quark Drive: Sunny Day/Electric Terrain active or Booster Energy used: highest stat is 1.3x, or 1.5x if Speed.
Very solid in Desolate Land, and with a Booster Energy, although it is only useful when boosting defenses, as there are better abilities for the offensive stats.
Punk Rock: This Pokemon receives 1/2 damage from sound moves. Its own have 1.3x power.
While definitely better than abilities like Iron Fist and Mega Launcher, you can certainly make an argument here, but it still struggles with consistency issues.
Sap Sipper: This Pokemon's attack is raised 1 stage if hit by a Grass-Type move. Grass Immunity.
Good when run on Swampert and other mons with a 4x grass weakness, but none of these are very viable.
Scrappy: Fighting, Normal moves hit Ghost. Immune to Intimidate
Definitely viable due to the high amount of Ghost types, but consistency brings it down to B tier.
Shed Skin: This Pokemon has a 33% chance to have its status cured at the end of each turn.
Another ability that I haven't seen much of but could certainly be good when used more. Gets rid of your toxic/burn which is nice.
Shield Dust: This Pokemon is not affected by the secondary effect of another Pokemon's attack
No scald burn, no rock slide flinch, no poison fang poison, no ice beam freeze etc. Good but inconsistent as it relies on your opponent getting lucky enough to a) roll the move, and b) get the roll for the secondary effect.
Sniper: If this Pokemon strikes with a critical hit, the damage is multiplied by 1.5x
This is really only reliable when used on Sirfetch'd/Farfetch'd, as they are the only mons who can use the leek, giving plus 2 crit chance, making them the most likely to get crits. Since that is the case, and those mons aren't super good, Sniper falls here.
Soul-Heart: This Pokemon's Sp. Atk is raised by one stage when another Pokemon faints.
Now don't get me wrong, I love Soul-Heart, but it is really only good when run with Innards Out Chansey.
Soundproof: This Pokemon is immune to sound-based moves, including Heal Bell
See Bulletproof
Speed Boost: This Pokemon's Speed is raised by 1 stage when another Pokemon faints.
Speed is certainly not the best stat when it comes to Metronome Battles. Sure, you will outspeed your opponents almost every time, but this causes you to also lose to Perish Song almost every single time.
Stall: This Pokemon moves last among Pokemon using the same or greater priority moves
I don't think this effects Perish Song so it's just not good. Just use a slow Pokemon.
Steely Spirit: This Pokemon and its allies' Steel-Type moves have their power multiplied by 1.5x.
Adaptability is better, but even then just use Intrepid Sword/Download. Much more consistency there.
Stench: This Pokemon's attacks without a chance to flinch gain a 10% chance to flinch
If this stacked with King's Rock it'd be decent
Super Luck: This Pokemon's critical hit ratio is raised by 1 stage
Somewhat inconsistent without Leek, but it's funny
Swift Swim: If Rain Dance is active, this Pokemon's Speed is doubled.
See Chlorophyll for explanation. Only better than other speed-boosting abilities because of Primordial Sea.
Synchronize: If another Pokemon burns/poisons/paralyzes this Pokemon, it also gets that status
While underwhelming due to the random nature of the metagame, it's not completely unviable since it takes those negatives that you get and shares with the opponent. It's a lose-lose scenario.
Tablets of Ruin: The Attack stat of all other active Pokemon is multiplied by 0.75.
Personally this one is borderline A and B tier, as I find it extremely useful when dealing with a lot of Mega-Heracross teams on ladder, pairing it with a special attacker, such as Mega-Venusaur or Mega-Ampharos.
Technician: This Pokemon's moves of 60 power or less have 1.5x power. Includes Struggle
Struggle being included on this can be clutch in some scenarios. Very niche but not completely unviable.
Thermal Exchange: This Pokemon's Attack is raised by 1 when damaged by Fire moves; can't be burned.
Could be very nice when used on your physical attackers, with the tradeoff of needing your opponent to hit their fire type moves.
Victory Star: This Pokemon and its allies' moves have their accuracy multiplied by 1.1
Missing is annoying, and this is certainly the best way to combat that.
Wonder Skin: Status moves with accuracy checks are 50% accurate when used on this Pokemon
Status moves are annoying. So just dodge them.