How to fight against Setsuka?
Stay safe > she's one of the best punisher in the game.
Don't whiff > she has a very good range.
Don't try to use moves when at disadvantage > her CH tools are very good (I recently put more 6K in my game, and god, that move is fucking awesome, same speed as a 2A, 65 dmg on counter, hard to punish, and it somewhat tracks upclose).
Don't duck > she has a lot of good mids, even if she throws you 36000 times don't try to duck, just break throws.
Don't understimate her lows > while visible on reaction, most people can't block it 100% of the time, even some player with a very good defense. 11A is one of the move I abuse (IMO it's a totally spamable stuff).
I have way more success with 11A than with 1A : 1) because it has great range and it's antistep 2) because it's slow (preventing GI happy opponent to get a good timing, or step happy opponent, opponent has to use step~G to beat it allowing you to throw more since throws catch step~G) 3) because it's a great TC used at a disadvantage. 4) even at advantage it somewhat SUPER TC against some mid moves (X's 44B, Mitsu's 4B, ...) 5) it can be used with the 236 stance, making it kinda hard to block on reaction, since opponents tends to focus against mid/throw after the stance. It also gives 11A a bit of extra range.
I am one of the people who say that she is S class.