@Overlord24 Ah, I just reread. Eryx slows depending on how fast things around him are going. If Avery did go his fastest it would unlock more of Eryx's potential so that could help. There's no way to surpass it though, his minds comprehension is (Technically) infinite. His attack power is limited to that of a regular human but defensively unless he's completely and utterly pinned, he's untouchable defensively. If somehow light moved slower than the speed of light, or had a build up, it would unlock the potential to slow things down to the speed of light, but light is always moving at light speed (Hopefully you understand) Point being, he can't be struck unless something completely silent caught him from behind. So probably Roxy
@KatherinWinter could sneak attack him if she was from the rear as I assume shadows make no noise as it passes through the air.