Anish, Book Burner

Flash, Trample
When Anish, Book Burner enters the battlefield,
you may counter target spell named Book
Burning. If you do not, target opponent puts the
top 12 cards of their library into their graveyard.
{1}{r}{b},{t}: Target opponent chooses one:
puts the top 6 cards of their library into their
graveyard; loses 6 life.