Dan, Delusional Weakling

You may exert Dan, Delusional Weakling as it
attacks. When you do, at the beginning of the
next end step, put a +1/+1 counter on Dan,
Delusional Weakling.
Remove three +1/+1 counters from Dan,
Delusional Weakling, {3}{r}, {t}:
Dan, Delusional Weakling deals 3 damage
to target creature.
"You should be my apprentice!"