Kalwor, Essence Shaper

Flash (You may cast this spell any time you could
cast an instant.)
Reach (This creature can block creatures with flying.)
Converge — Kalwor, Essence Shaper enters the battlefield with a +1/+1 counter on it for each
colour of mana spent to cast it.
{g}: Add one mana of any colour to your mana
pool. Tap Kalwor, Essence Shaper.