Pokemon Violet - 7* Pikachu the Unrivaled rerun with Ogerpon

As part of the summer events, 7* Pikachu's being rerun! It was quite a fun raid with a cute gimmick.
As a reminder, 7* tera water Quiet Pikachu (with x50 HP in a 10-minute raid) immediately puts up a shield covering 100% of its health bar, then follows up with Rain Dance and then Surf, all before you can act. Its regular moveset is Thunder, Surf, Play Rough, and Iron Tail, and it's even holding a Light Orb to double its attack stats! Its fixed actions are fairly tame though: with 80% time remaining Pikachu steals a tera orb charge and wipes its own debuffs, then at 65% time remaining it steals another tera orb charge, and at 65% HP remaining it wipes its own debuffs again... and below 40% HP it starts having a 50% chance at acting again. Instantly putting up shield plus wiping its own debuffs twice incentivizes you to buff yourself instead, but having to buff both defensive stats is awkward too.
However... the raid has actually been nerfed since the original run.
Originally, the shield reduced non-tera damage by x0.01 but then boosted any terastallized damage to x1.2!
In this rerun, the shield is normal and reduces non-tera damage to x0.2, terastallized but move-type-not-matching-tera damage to x0.3, and terastalized matching damage to x0.7.
As such, if you somehow faint post-terastallization then the raid doesn't become impossible anymore... but if you ARE terastallized then you're doing noticeably less damage than you would have in the original, which is quite a shame.
(Also it seems like Pikachu originally had EVs of 252 HP/252 SpA/4 Def but now just has zero EVs.)
Anyways, my original strat was to use Sawsbuck for a slow-but-steady strat: simply spam Horn Leech, terastallizing as early as possible and using Swords Dance whenever it's safe.
The list of Pokemon that learned Horn Leech was fairly short back then: the only alternative to Sawsbuck was instead Gogoat, who merely learned Bulk Up instead of Swords Dance.
Post-DLC though, we have other options! Trevenant also gets Horn Leech but no Swords Dance... but more interestingly, it gets Knock Off instead, easily allowing you to survive Pikachu's moves.
But most importantly, final option Ogerpon has access to all three of Knock Off, Swords Dance, and Horn Leech! It's very clearly the optimal counter for this raid. (Defiant proccing on Play Rough or Iron Tail random debuffs is very nice... though sadly you lose that ability once Ogerpon terastallizes. I got lucky this run though!)
I deliberately reset for a Bellibolt because I read that it doesn't actually use Discharge and activate Lightning Rod constantly... but that's not quite accurate. It seems like the ally AI is 'blind but smart' like the 7* Pokemon themselves, in that it does use Discharge once, then recognizes that it's absorbed and then never uses it again... and Light Screen upkeep for halved special damage probably makes up for the singular +1 SpA from that one Discharge. Arboliva, of course, is also very handy to buff your grass moves while simultaneously giving some chip healing (enough that I didn't even bother to use Horn Leech this run, hah).
Oh, and of course, as a modern 7* raid (rerun) the raid drops also now include a total 15% chance for any herba mystica! Way better to farm this than 7* Charizard or any other new 7* raids, and you have two full weeks for it, so go nuts.
An interesting strat I've seen for multiplayer is having Weezing's Neutralizing Gas negate Lightning Rod and then bringing in Miraidon for brute strength. They're still in danger from Play Rough, but it sure sounds fun.