Tommy, Filthy Casual

Whenever you cast an instant or sorcery spell,
you get an experience counter. Then, if you have
five or more experience counters, exile Tommy,
Filthy Casual, then return him to the battlefield
transformed under his owner's control.
Tommy, Filthy Casual's power is equal to the
total number of instant and sorcery cards
you own in exile and in your graveyard.