edit: wanted to say 3k character limit sucks
AMEN

I love your idea of how Blood and its gauge skills would work! TBN's idea of "turning pain into blood" actually blends with that very nicely too.

As for Bloodspiller animation. I personally love the animation. Slamming it into the ground feels satisfying to me! It's just it's not the type of skill to be spammed 5 times in a row lol.