Part 0: Motivation
Now that HOME compatibility has been out for a month, I feel like something that has been taken for granted with the popular builds for this raid is accessibility. If someone is looking for a solo Pokemon available in both Scarlet and Violet that spawns naturally with its base tera type, without a mutually exclusive starter choice or trading or transfers from other games, then there really aren't many solo options out there in discussions. The main talk is either with HOME transfers or version exclusive mons. This is why I wanted to win with a mon of the people, for everyone out there who can't play online with anyone or get any version exclusives.
This post is still actually about another Azumarill solo again, but this was not as easy as expected. Before it dropped, I thought this would be an easy clear to show who the better Fairy was. However, gamefreak actually put the pressure a lot higher with the shortened time, double moves, and multiple problem points. I ended up having a good feel of when I could set up as a result, so this post will cover my general intuition and practical notes of my winning attempt. My Azumarill set is the same as it's been for other raids, featuring the Shell Bell and Amnesia/Play Rough/Belly Drum/Mud-Slap to deal with just about everything a special attacker does, but the timing was still tight and there was a lot to figure out in between.
Part 1: The Beginning
In the blind runs of this raid, I started off floundering and running out the timer. Seeing Will-O-Wisp in the main moveset and Fire Blast for the first time was unexpected, and an early shield plus the Nasty Plot midway through the timer was disheartening. After some initial failures dealing with burns, Facade was proposed in the smogon raids channel and I thought that my Normal tera Azumarill that I used in my playthrough could take the most advantage of it. In the end this was not how I won the run since I realized that I could just avoid being burned for the majority of the raid and being burnt was actually a major issue both damage and time-wise, but I learned a lot of lessons through spamming those attempts that I used in my winning run and I will go over those experiences.
Part 2: The Failed Attempts
My moveset was mainly staying the same, but I was getting a better sense of when to set up with my buffs and debuffs though not to much success. One main lesson I learned at this point was that I was spamming Mud-Slap so much and using heal cheers so that I wasn't actually ending up burned when I was ready to start trying to go for the kill and missing out on enough damage. There just wasn't an opportune time to get burnt as I had to hit a lot of Mud-Slaps that I didn't want to be burned for but I also couldn't really get burnt after setting up Mud-Slap, so I ended up trying to win without getting burnt which I just didn't have enough damage to finish with. At some point I realized that I could just go back to tera STAB Fairy moves if I wasn't getting burned anymore, but I still kept trying Facade strategies for a while, and I did end up making another significant investment that won me the raid.
(My closest failed attempt with Tera-Normal Facade.)
Part 2.5: Rigging the Game
Partway through Part 2 but before I switched back to Fairy, I realized that AI Bellibolt was the factor that was making or breaking these attempts. Speed control with Mud Shot and Discharge being the only possible source of paralysis through the shield was a game changer, allowing me to set up before Delphox got to move and prevent Delphox from moving entirely. Potentially interrupting Nasty Plot and Magic Room and double attacks were also appreciated bonuses.
What I ended up doing was saving at a 3 Star Steel Haunter raid and using the "join a group" option, which locks in all the AI choices for future raids. I would reset if the AI did not roll Bellibolt, since you can't run from raids started as a group. I wanted to avoid Umbreon and Gardevoir due to Synchronize passing on burn, as well as Arboliva for grassy terrain using up precious time. I thought Sylveon's Moonblast SpA drops could have also helped mitigate Delphox's damage output, but Amnesia handles that for most of the raid and once Delphox gets below 60% HP to reset your buffs, you're basically in the endgame anyway and have to bank on dodging.
This process took some time, but it was mostly idle and I felt it was better invested to get Bellibolt consistently instead of running on completely random AI and hoping to get Bellibolt. I also got Heracross who was not particularly noteworthy and Arcanine who had a 10% chance to burn but also could put some Leers up, though it probably didn't really matter much in practice.
Part 3: The Strategy
At this point I had fought Delphox many times and had strong feelings on when to do what. My general gameplan was to start off with Amnesia, then one Mud-Slap just to get it below 100% accuracy, then finish setting up my SpD with 2 more Amnesias. Around then I would heal after the shield went up and try to sneak a Belly Drum in early, which could end up taking another heal cheer to replenish. Afterwards Delphox gets to the point where it resets its debuffs, and that's when I have to set up as many Mud-Slaps as I can ideally before it gets to Nasty Plot, and also after a tera charge steal though I usually don't have all 6 up by then. When I feel safe enough, this is when I have to start going on the offense and activate the tera STAB Play Rough. Ideally a Water Azumarill would be better to resist Fire Blast and have 100% accurate Liquidation STAB, but this is just the Azumarill I've been rolling with since Charizard. It takes a few hits to chip through the shield and Delphox will end up resetting buffs + Magic Rooming + double attacking around after it goes down. I had attempts where I tried to re-setup Amnesias with Facade since I wasn't doing enough damage, but there was usually not enough time to finish the job. The main strategy I had at this point was to just reset Belly Drum immediately and hope Delphox doesn't land any hits on me and just try to win from there.
Part 4: The Final Cut
In my first run back with the Fairy Azumarill again, I ended up taking 2 heal cheers after the shield went up to be safe. After the Belly Drum I got burnt, but Delphox had just reset its stats so I went for Mud-Slaps instead. I ended up cutting it very close at this point going into red HP from Psychic and fortunately rolled high on my heal cheer to 172 HP, while Bellibolt finally landed paralysis and I blocked Nasty Plot from going off. At this point I felt safe about going for all 6 Mud-Slaps to completely neutralize Delphox, though it did land one Psychic at -5 accuracy which was acceptable. As long as there was no burn, there was still a chance.
(left: before Mud-Slaps, right: after Mud-Slaps and terastallizing)
It took some time, but after all was said and done, there was nothing else to do but finally start to tera on the offensive and see if this run would pan out. The tera STAB Play Rough took about 3 hits to break the shield. After breaking through the shield, Magic Room did get through the paralysis, but I immediately took advantage of Delphox missing a turn after the shield break to reset Belly Drum again, which was right when a tremendous energy started gathering again.
Play Rough did half of Delphox's remaining health, more than I'd ever seen Facade do. I'm not sure what Delphox did end up landing a last ditch Fire Blast through paralysis and -6 accuracy that almost took me out in my half-health state from the second Belly Drum usage, but Azumarill held on and just had to land one more Play Rough to deal the final blow, and so it did.
Part 5: Conclusion
Overall I think gamefreak did a pretty good job with this one despite my struggles with it. The moveset was not packing any of the expected coverage, but was still a pretty tough challenge for solos, and the lower timer really puts a crunch on classic setup strategies this time around. Azumarill only managed to win this one because of hax preventing Delphox from doing anything, and even then it was down to the wire.