Insidious Plague

When Insidious Plague enters the battlefield, put a -1/-1 counter on each creature.
Whenever a player gets one or more {e}, proliferate. (You choose any number of permanents and/or players with counters on them, then give each another counter of a kind already there.)
Yawgmoth's diagnosis of powerstone radiation exposure as the cause of Phthisis was met with s