Tu'gali, God of Forgotten Wars

Haste
Finale - At the beginning of your postcombat
main phase, if you have 10 or less life, untap all creatures you control. After this phase, there is
an additional combat phase.
At the end of combat on your turn, Tu'gali, God
of Forgotten Wars deals X damage to you where
X is 5 plus the number of combat phases you've
had this turn.