spell worked the first few times (casted on Arch Liches, gave the stack + the modifier), have it at expert level and should create 2.15 the stack targeted, now it does 0.18 the stack, I have 86 and I get 16 from the cast - I have varied the size of the stack and the ratio has never gone back to the correct amount vs spell description...
if this is a game fix to lower a very powerful spell then the spell description is very wrong and the spell is not worth the mana cost.
otherwise - massive bug.