Quraillo, The Rainbow Dragon

Quraillo, The Rainbow Dragon enter the battlefield with x +1/+1 counters, then double its
power and toughness
Flying
Quraillo, The Rainbow Dragon can't attack unless
its have power of 5 or less.
{x}{x}{x}: Put x time 2 +1/+1 counter on Quraillo,
The Rainbow Dragon
Remove 3 +1/+1 counters : Add two mana of any colour.