bloodmarked Ancient

Pay X life, the bloodmarked Ancient's
power and toughness are X.
When a creature of yours is put in a graveyard
you may sacrifice bloodmarked Ancient,
if you do return the other creature to the battlefield. This only
works if it was put in the graveyard on the turn
you sacrifice this creature.
It has seen empires rise and fall and now it is here
to witness a great re birthing.