IMO,
Blood Sucking is supposed to be dps skill,
on a normal geared, corona rod+0,
lv5 Blood Sucking + Full Buff, 5k x 19 hit = 95k
heal by 30%, 5k x 30% = 1.5k / hit-mons
u got a vampire mini-aoe frost cloud.
if u gonna make combo with frost pillar, i don’t think if bloodsuck is matching with frost pillar mechanism.
low aoe range <-> rounded crowd control
channeled skill <-> 1% freezing chance, it’d be easily for mobs to break your channel.
high SP cost <-> rounded crowd is bigger than BS hitbox, just half of it.
by 1 hit, u need to wait another 40s and lose the chance to heal atm.
but if you just going pillar and blow, make sure u don’t instant kill the mobs, so u can heal yourself.