Fulcrum, Dissonant Assasin

Shroud, First Strike

{1}{b}: No Hesitation (Fulcrum, Dissonant Assassin gains your choice of deathtouch, wither, or shadow until end of turn)

{t}: Fulcrum, Dissonant Assassin deals 1 damage to target creature you do not control. When a target creature dies this way, you gain an experience counter.

Fulcrum, Dissonant Assassin gets +1/+1 for every experience counter you have.