So, the bug is simple and straight foward.
The description of the skill its saying that it will consume 5% of your HP (lv5).
I did the testing, and the skill is actually taking 20% of my HP in total.
The skill should give you ATK (which I think its normal) and also ASPD (which is also bugged, not giving you anything).
Follow bellow the steps that I did:
normal buffs only (check HP and ASPD):
Its a weird math there!
I don't know if its cancelling the rising dragon buff... But its not normal to decrease 20% of the HP.
Thank you in advance!