R3 Kate Bishop SOLO’S ABYSS THING and controls his rock stacks with an underrated ability 

bullseye's bleed works therefore I'd say that it should work for Kate too - although there's a cooldown on the caltrops ability so probably won't be as broken

Don't need that

U can't do with 4 star black CaT

dont remember if she was high sig back then so cant attest lol looking at the coldsnap damage tho i dont think she was even sig 60