Corvish Ail, Of the Wood

First Strike, Haste, Affinity for Elves
Whenever Corvish Ail, Of the Wood attacks you
may choose which of your target opponents
creatures blocks Corvish Ail. If you do not choose
a creature to block Corvish Ail, your opponent
may chose its blocker.
Corvish Ail may only be blocked by one creature.
I have seen him dance around the battlefield, choosing
his targets during the violent chaos around him.