Graveto, Fate Defier

Haste, Double Strike, Manence
{b}{r}: Graveto deals 1 damage to
each player
Whenever Graveto deals damage to a
player, you may pay{u/b}{u/r}{b/r} and X life.
If you do, you may cast target instant
spell with mana cost X or less from that
player's graveyard without paying its cost