Juggle to Ultra combo with Boxer is for guarantee damage, I know go for it alone is good, but most of the time its not guaranteed except from Stun (which is same as juggle to Ultra damage wise) or Crumple Stun but thats hard, opponent will jump...
Throw break him and yeah headbutt reversal him, invincible frames at startup and also instant tech jump and play it safe don't jump in on him, fadc his fireballs, make him jump to and use a crouch HP, spam that crouch HK at mid to long range, its safe.