Tyler, Gooning Champion

Gooner-When Tyler, Gooning Champion enters the battlefield, roll a d20. Whatever you roll becomes his power/toughness.

Stroker-{4}{t}: Whenever Tyler, Gooning Champion attacks add a stroke counter. As you pass each threshold gain each effect:
•1-Add a +0/+2 counter at each upkeep.
•3{dash}Add a +2/+0 counter at each upkeep.
Release{dash}10{dash}Deal damage equal to Tyler’s attack power to target.