Cyclical glutton
Whenever a +1/+1 counter is removed from a creature you control by
a -1/-1 counter you control, you may search your library for a
basic land card and put that card onto the battlefield
Counterphasing (this creature enters the battlefield with a
+1/+1. At the beginning of your upkeep, if this creature has no
+1/+1 counters on it, you may put a +1/+1 counter on it. At the
beggining of your upkeep if this creature has a +1/+1 counter on
it, put a -1/-1 counter on it.)
Card Comments