Can multiple Kata's be used in the same action?
I figure that most that have activation based on making an Attack, that they cannot, because there are some very specific things that those require: Martial Art [Melee] or Fitness (Void) or what not. But there are others, such as the Striking as [Element] kata that their activation is "spend opportunity and get X" They do not require a roll in and of themselves, but are more like "hey, you have this kata so these are other uses for opps you can do"
For instance, could a bushi use Iaijutsu: Rising Cut, could he also use Striking as Fire as well? And if you had the opps left, could you use Striking as Water as well?
I guess one could argue that, with the Strikign as [Element] Kata, and other kata that are 'based' on one of the elements, you would have to be in the stance that coresponds, but thematically, mixing and matching what one learns in a marital art, is how you make that art your own.