Blood Aspirant 

Creature — Satyr Berserker
Whenever you sacrifice a permanent, put a +1/+1 counter on this creature.
,
, Sacrifice a creature or enchantment: This creature deals 1 damage to target creature. That creature can't block this turn.
Legality
standardNOT LEGALpioneerLEGALmodernLEGALlegacyLEGALvintageLEGALcommanderLEGAL