User blog comment:Yarrghman/Seth, the Sand Mage/@comment-4948122-20130329144042/@comment-6353331-20130401063852

It is flat +125% per second- only when cast by itself. If Whirlpool is cast in Quicksand, the next tick of Quicksand that would have done damage is revoked, and all affected enemies are affected by Whirlpools enhanced effect. Using W trades heavy damage for hard CC.