Deidre, Light of Battle

Unbreakable (A creature with unbreakable
can't be removed from the battlefield by opponents
with a life total equal to or above its controller's.)
As long as Deidre, Light of Battle is on the
battlefield, your life total cannot go below 1.
If your life total would go below 1, you may cast
Deidre, Light of Battle as though it had flash.
"You will not break me, Betrayer."