Lokuama, the final Word

Defender, hexproof
Whenever a card is put into an opponent's
graveyard from their library, if it does not share a
card type with another card put into that player's
graveyard this turn, you may draw a card
{x}{u}{u}, {t}: Fateseal X, then target player puts
the top three cards from their library into their
graveyard. {x} cannot be 0.