I'm not going bother you with playstyle ideas, I'll leave that to you since you seem to enjoy figuring it out but I got a few visual ideas that might give BST a unique flair.

What if instead of a shield they use a thick chain instead, that acts like a makeshift shield when rolled around the arm? It could also be attached to the axe for a burst phase for example.

I also believe that the beast companions should be unique creatures like Dawon and max 3 creatures of varying sizes.