[1.2.379] More Magician Tweaks

The cooldown only makes sense, otherwise you'd just spam Glacial Chain. This adds some variety, much like Dark Lightning does for BMs.

I never use Dark Lightning because... IT HAS A COOLDOWN! I get along on my BaM just fine switching between chains and quinstrike, I don't see why I can't do the same with my IL.

edit: to be clear, I would rather it be nerfed and have no cooldown than have it ridiculously strong WITH a cool down.