Here to post a streak of 122 wins with Greninja, Scizor, and Garchomp.
Greninja @ Life Orb
Timid
6 HP 252 SpA 252 Spd
Surf
Ice Beam
Extrasensory/Dark Pulse
Grass Knot
The king of fast special sweepers. If you want fast battles where your lead can often 3-0, you want either this guy or Landorus. Greninja doesn't roll over to a certain type attack, which is nice, and is actually fast. Mons with decent Sp Def that you hit neutral are only 3HKOs though, you don't have the sheer force that is Earth Power.
Greninja does not joke around though- the coverage is wonderful, and he hits with hard SE attacks on a lot of stuff. Fast Electric attacks are the main worry.
I started with Extrasensory and switched to Dark Pulse after battle 100 or so. Dark Pulse is way better offensive coverage, but with Extrasensory you can kill with Ice Beam and be ready to resist what they throw at you next. Every Tom, Dick, and Harry gets legends these days- so I think the Dark coverage is nice for Azelf, Mespirt, and Uxie especially.
If I cared about getting a long streak with this team, you would switch to Scizor on anything he can set up to +6 on, but...eh.
Scizor @ Scizorite
Adamant
252 HP 252 Att 6 Def
Bug Bite
Bullet Punch
Swords Dance
Roost
Scizor is still great, but it seems there are more strong special attacks in the Tree. He does bring good priority and a Toxic immunity. Aegislash would be terrible for this team since I do not have something to take an EQ for him. You have to be smart setting up, as if he goes down while boosting it is often game over, since there are a lot of threats that slaughter your team if not for Scizor standing in the way. The halcyon days of easy +6 are over- so be content with your +2 and Bullet Punch away.
Garchomp @ Choice Band
Jolly
6 HP 252 Att 252 Spd
Outrage
Earthquake
Iron Head
Rock Slide
I need a Electric immune, so here we are. He is just fast enough to use a Choice Band well, with the catch that this guy can not be your last pokemon against unknown AI mons. The Ice weakness is a serious issue- Boltbeam is everywhere and sometimes you get blasted trying to be cute with the switches- Icy Wind ended my streak since I though Regice would T-Bolt Greninja. Garchomp either feels like a burden or the only mon that holds the team together. Attacking with him is a commitment- as soon as you know Garchomp will be in, you have to think about your next move if something disastrous happens after your KO.
You are sometimes handsomely rewarded for your sacrifice of using this beast. Garchomp 1- deletes stuff while being fast and 2- lives through stuff while damaging the opponent.
This is the exact same team I used in the Maison. I might do another attempt before USUM comes out, but I might try some lesser used mons for fun.
Edit: Now with 100% more proof-
https://i.imgur.com/CM9fqFK.jpg