Tiamat, Endbringer

Flying, Immortality(When this card enters the graveyard
or exile, you may pay {0}. If you do, return this card to
the battlefield)
{t}, {w}, {u}, {b}, {r}, or {g}: Search your library for a
target non- instant and non-sorcery card with a color
that matches the color you paid for to activate this
ability. Then shuffle your library.
Your doom is inevitable, fools!