Here is my attempt at a tier list: (not really sure how to place Soul of Devil Jin)
Top: Alpha Pat, Omega, Algol
High: Viola, Cervantes, Patroklos, Pyrrha, Nightmare, Natsu, Astaroth, Mitsurugi
Mid: Ezio, Ivy, Hilde, Xiba, Voldo, Yoshimitsu, Aeon, Leixia, Maxi, Tira, Dampierre
Low: Z.W.E.I, Raphael, Siegfried
A few notes:
- Cervy is not top tier because of his unsafety. A competent player that knows how to fight Cervantes will destroy him (Just Guards, Punish, Whiff Punish). His key tools are all unsafe, and a competent player can bait out his iGDR and heavily punish him for it.
- Viola requires meter to do damage, and if read correctly, she can get zoned by Algol or Nightmare.
- Algol is top-tier material simply because of his insane damage output (that does not require Counter Hit or a wall). He can hit you for 120+ damage off a whiff punish/GI/Guard Burst, without the use of his full CE. not to mention an i16, 70 damage combo starter that can be a Clean Hit (quite possibly clean hit A) from full crouch! He can control the arena like no other character in the game with the bubble zoning and his 4B+K that catches ANY RETREATING MOTION/ATTACK (like most character's 1A, back step, or back side-step). The reason people don't place him at the top is simply because no one has fully utilized all of his tools and his potential.
- Astaroth is simply high tier only because he can kill you with 50% meter and could go for a tech trap as he is killing you. Also the fact that if you can guess correctly with his grabs, you will own the opponent in close range (with few exceptions), and can zone the opponent until he/she is frustrated and makes a mistake, costing them the match.