Ahlih, the Profane

Rot (Each card you put from the top of your
library in to your graveyard while casting this
spell pays for {1})
{g/u}{g/u}, {t}: Add X mana of any color to your
mana pool where X is equal to the highest
converted mana cost among cards in your
graveyard. Until end of turn, instant and sorcery
cards in your graveyard have flashback. Their
flashback cost is equal to X. Creatures cards
have Unearth. Their Unearth cost is equal to X.