Cyl, Voldaren Banneret

First strike, trample, haste
Whenever Cyl, Voldaren Banneret attacks, it
gets +X/+0 until end of turn, where X is the
amount of life defending player lost this turn.
Whenever Cyl becomes blocked, sacrifice it at
end of combat.
Pay 13 life: Return Cyl from your graveyard to
the battlefield tapped. Activate only as a sorcery.