[1.2.378] Magicians in Jump

I think you misread. It changes from a 60% resistance to giving improved DoT, etc.
Extreme Magic can work for I/Ls if we're killing with a Hero or DB, I'd think.

Fire, Poison Resistance 60% increase in property

Read the incorrect line, disregard.

I'd rather not have to rely on a Hero or DB if they can Darknen, why can't my DoT help me too?

Hoping "freezing" indicates ice DoT (unlikely).