Ugin, Brother of Bolas

Ugin, Brother of Bolas enters the battlefield with
1 +1/+1 counter for every color of mana spent to
cast him. If he has 2 or more +1/+1 counters,
he has flying.
{5},{t} For every color of mana spent to cast this,
put a +1/+1 counter on Ugin, Brother of Bolas. Activate once per turn, and only as a sorcery.
If Ugin, Brother of Bolas has 11 or more +1/+1,
exile him and return him to the battlefield transformed.