Jacaroe I've come to let you know that Santa is real, and he is me, I am Santa, your secret santa that is.
Anyhow, the request came for an aggressive Mimikyu Fairy. I just finished laddering to 1500s with it, discovering along the way just how much scizor, bug, and steel is on the ladder along the way, and here are my thoughts on both the team, how I built it, and secondary move options and changes I made along the way.
link to The Team:

The mon the team was built around. I figured here to let mimikyu do what it does best - as a SD sweeper and failsafe with it's ability disguise. I initially opted for a moveset of SD/Play Rough/Drain Punch/Shadow Sneak, but I actually found pretty early into the ladder run that Shadow Claw was often more favorable to have than Drain Punch. Alot of walls, and most notably the poison types that give fairy trouble, aren't threatened whatsoever when Mimi had D Punch as it's coverage option, and there are a fair amount of offensive threats and mons that Mimi hits harder with Shadow Claw as well. Normally I opt for Drain Punch on Mimikyu, but the team already handles steel fairly well so I figured it wasn't an issue.

When hearing "aggressive Mimikyu Fairy", I figured Screens - a stable for Fairy - was the way to go here. This is a pretty standard Klefki set, Foul Play chosen over Thunder Wave because I figured as a ladder run I'd especially need Foul Play for the lower ladder Scizors where bug is more common, and I'm a fan of the move on Klefki anyhow to help prevent it from being passive.

Primarina, especially in today's meta, is a top mon for fairy. I figured on this build I'd be able to drop Azumarill - it would be a bit hard to fit, and more than anything Primarina helps with matchups that I need cover more at least in my opinion. I initially started with a bit wonky resto chesto set to see if it'd work, turns out it doesn't and classic cm+3 attacks is just better here. This is a mon that kicks ass in a whole bunch of matchups, and especially behind screens is a serious threat at your disposal. I put some speed evs just to make sure it outpaces some mons like the steel birds, outpacing up uninvested base 70's.

Since Mimikyu itself isn't too strong of a setup sweeper, I figured this was the slot where I'd need my wallbreaker. Initially I considered Specs Flutter, but especially at higher ladder I consider Specs Flutter a set that doesn't break the balance builds I'd probably struggle more with, so I opted for Mixed Iron Valiant. Idea here being E-Belt with ice punch, tbolt, close combat, and moonblast would corebreak common defensive cores on types such as Water and Flying, and ideally allow the setup sweepers to clean as a result. Life Orb is a serious option to consider, especially without max special attack, it would definitely help with alot of rolls vs. mons like Corv.

With Valiant as my wallbreaker here, Flutter becomes my speed control option on this team. Moonblast/sball are givens, tbolt chosen for it's coverage, initially I opted for psyshock in the last slot but found it unnecessary and chose Power Gem to help with the fire matchup which I noticed could be improved.

Lastly, Hatterene, this is our hazard control, secondary cm sweeper, and probably the set that I changed the most on the run. When I initially started out, I had magical fire on this slot over giga drain - I figured I would be able to handle types that nuzzle or giga would hit without much issue at low-mid ladder, but I was still scared of the threat that many common steels posed. As a result I initially started with magical fire, tried babiri berry as an item for a few games - it was unnecessary - same with covert cloak, before finally landing on Heavy Duty Boots to help ease the stress on Hatt from hazards it may not be able to come in on. Giga Drain I pushed in over Magical Fire as I got to higher ladder - With Primarina + Foul Play Klefki, Magical Fire was a bit overkill to check mons like Scizor and whatnot, and ultimately decided to switch to Giga Drain to help with bulky waters and grounds that I figured would pose more issue to me as I reached upper ladder. The speed evs are simply here to make sure you're faster than Toxapex.