Magnamalo, Wyvern of Malice

Hellfire Buildup - When this creature deals damage
to a creature, that creature gets -0/-3. This ability cannot destroy a creature. This ability can destroy planeswalkers.

Hellfire Blast - At the beginning of your end step, if Hellfire triggered this turn, this creature deals 3 damage to any planeswalker or creature affected by Hellfire.