Well that was the best OMOTM in a while. Got some fun sets that I figured I'd share.

Qwilfish (Gengar) @ focus sash
Ability:Intimidate
Evs: 4 Def/252 SpAtk/252Spe
Timid Nature
-Taunt
-Spikes
-Shadow Ball/ Toxic Spikes
-Sludge Wave/Toxic Spikes
Qwilfish is a great donor for Gengar. I ran taunt, spikes and dual stab as a suicide lead but intimidate is useful with toxic spikes if you want a more midgame oriented hazard setter. As a midgame setter, blocking rapid spin and defog with a ghost typing and taunt are pretty useful qualities too.

Accelgor(Chansey) @ Eviolite
Ability: Sticky Hold
Evs: 252 Hp/252 Def/ 4 SpDef
Or 4 Hp/252 Def/ 252 SpDef
Bold Nature
-Spikes/Toxic Spikes
-Toxic
-Recover
-Final Gambit
This looks incredibly gimmicky but honestly this thing put in serious work. With such easy access to spikes and rapid spin in this meta I found hazard stacking to be really useful and Chansey does what Ferrothorn does in Ou, comes in on something it walls and sets up spikes. Accelgor gave other useful attributes too. Reliable recovery is always nice and Sticky How was really useful as a Chansey can't afford to lose eviolite. Finally, Final Gambit is more useful than you'd think. Played correctly, I could remove one Pokemon from the opponents team that I otherwise struggled with, in particular mons that chose to set up I'm front of a Chansey that they presumed couldn't hurt them. A gimmick for sure, but an effective one.

Hitmontop(Lopunny) @ Lopunnite
Ability: Intimidate ---> Scrappy
Evs: 252 Atk/4 Def/ 252 Spe
Jolly Nature
-Fake Out/ Quick Attack
-Frustration
-Close Combat
-Rapid Spin
Continuing on with our theme of hazards and their removal, here we have Mega Lopunny with my patented Scrapid Spin™. Hitmontop let's you use a pretty much standard Mega Lopunny set except with CC over HJK (which I prefer but it gets HJK too) and crucially, Rapid Spin which allows it to be the only unblockable spinner. While this isn't the most significant of niches but it can do other things too. As a rapid spinner it is excellent, forcing switches with intimidate and the fact that Mega Lop threatens a lot of stuff for free spins. It also does what Mega Lop does in OU, destroying offensive teams without a favourable scarfer as little outspeeds it otherwise and acting as a great cleaner if you save it for the late game. Quick attack can be more useful than fake out but I was running toxic spikes with it and racking up some more poison damage was sometimes too important to pass up. Really useful set that merits the place it has in the VR.

Jirachi(Mawile) @ Mawilite
Ability: Serene Grace ---> Huge Power
Evs: 252Hp/252 Atk/4 Def
Ivs: 0 Spe
Brave Nature
-Iron Head
-Play Rough
-Fire Punch/Ice Punch/Thunder Punch
-Trick Room
Trick room Mega Mawile is exactly as strong as you'd think it is. It has an easy time getting trick room up because there's not a whole lot that stays in on Mega Maw and then you've got four turns to wreak havoc. Jirachi gives it dual stab (shame meteor mash is illegal) and elemental punches for some nice coverage. No Swords dance makes it less of a wall breaker and it missed knock off but if you play your cards right this thing will blow a hole in your opponents team.

Golem A (Rotom H) @ Lum Berry/Choice Scarf/Air Balloon
Ability: Magnet Pull
Evs: 252 SpAtk/4 SpDef/ 252 Spe
Timid Nature
-Fire Blast
-Thunderbolt
-Earth Power
-Magnet Rise/ Volt Switch
A thoroughly obvious but still effective mon with two sets, both of which do one thing: kill Celesteela. Stopping other steel types is a nice boon too but I can't stand normal Celesteela anyway so it's prominence in this meta quickly got on my nerves. It's dual stabs means that even if it's got an ability that makes it immune to one of them, you can still kill it. Earth power is useful against other steel types that may be running an immunity ability like flash fire that you couldn't hit as well otherwise and also Rock/Ground types I guess. Lum Berry helps with sleep powder from Vivillon variants of Celesteela and in conjunction with an immunity to burns and paralysis make it a good status sponge. Air Balloon and/or magnet rise helps with it's ground weakness (which is more useful in other matchups but helpful nonetheless) Choice scarf makes it a better Pokemon outside of it's role as a steel trapper as I found it to be lacking otherwise. Freely accessible magnet pull means a lot of teams don't bother with steel types and I found the scarf version to be less of a dead weight against those teams.