IGN : Sly / Pepperjack
Reason : Either hitbox and/or aimfix. I'm not entirely sure, but something is definitely off.

Evidence :

Screen shoots - https://imgur.com/a/qRBwLZa

Watch this replay of a couple rounds to get a grasp of his game-play - https://www.sendspace.com/file/d9jry0 .
Imo this clip is already enough to prove that he's unlegit.
He doesn't aim at all. Just shoots randomly and at times ends up hitting without the actual HIT. At times he even shoots when there isn't anyone to shoot at. Does way too much damage for someone who plays like a random.
Also he either hits super hard or no hits at all. Nothing in-between.
Consistently does incredibly high damage every round (even with one red shotgun) when he wasn't playing nearly capable of it until the last week or so.
Such high, consistent damage output is not possible even for top tier players with this v8 hitbox and any experienced player will agree to the same.

Evidence 1 :
Edited clip - https://gfycat.com/GranularNaiveGopher
Original clip - https://www.sendspace.com/file/xmjcab

Does a instant 1v2 without hitting any of us. Dmg done after 4 shots is 320. He shoots the opposite wall and Opertunisc dies instantly; misses me entirely as well [in the 3rd round of the replay]

Evidence 2 :
Edited clip - https://gfycat.com/BlandGloriousDormouse
Original clip - https://www.sendspace.com/file/l5bwvt

Enters base with 0 damage. Goes in and only hits 2 shots. Dmg done after is 266. Max damage is 264 with 2 limitbreakers.

Evidence 3 :
Edited clip - https://gfycat.com/CookedPointedEstuarinecrocodile
Original clip - https://www.sendspace.com/file/xgag65

Enters base with 315 dmg. HITS one pb, proceeds to miss everything else, hits his last random shot. Dmg becomes 625. Dmg dealt is 310. Seems like his pellets redirected on missed shots and accounted for the extra damage somewhere.

Evidence 4 :
Edited clip - https://gfycat.com/ShadowyFarflungAsiaticmouflon
Original clip - https://www.sendspace.com/file/o0yt1x

Starts off with 77 damage. First hit to mummy barely does anything as more than half the body was already covered by the wall(and you can see pellets landing on the wall instead of opponent). Proceeds to 1v1 guy in yellow pants. Gives 3 hits and kills him. Damage counter is now at 392. Which means he did close to 300 to a single guy, which is impossible. Only plausible reason to this is that his shots that missed were doing damage to the mummy too.

Evidence 5 :
Edited clip - https://gfycat.com/PeriodicHarshKitfox
Original clip - https://www.sendspace.com/file/p9g23h

Starts with 583 damage on the scoreboard, goes out into the garden. Tries to hit Tsumei 3 times but none of them HIT. All shots completely landed on the green parts of the garden.
He had 679 damage after those 3 missed shots before he went inside to chase Tsumei near the water/AP area. Does another 96 damage before dying on top of the 679 somehow, without hitting any pellets.
If you observe these screenshots https://imgur.com/a/5VhtU4o from the replays very carefully, you'll be able to count all 12 missed pellets for all 3 shots on the ground/walls.

Evidence 6 :
Edited clip - https://gfycat.com/ShockingWellmadeDevilfish
Original clip - https://www.sendspace.com/file/zy92mn

Starts with 56 damage on the scoreboard before killing Aeonflux13 and ends up with 388 damage after. Didn't shoot or slash anyone else. 56->388 = 332 damage increase after hitting and killing ONE person that didn't heal. Where did the other dmg come from?