Val - Lord of Misrule

Sow Chaos — When Val-Lord of Misrule enters
the battlefield, put a chaos counter on up to
X target creatures, where X is the number of
cards you own in exile. Goad those creatures.
Reap Chaos — When a creature with a chaos
counter on it dies, exile the top card of your
library. You may play that card for as long as it
remains exiled.