The Chromatic Heir

Flying, Haste
The Chromatic Heir enters the battlefield with a
+1/+1 counter on it for each color of mana spent
to cast it.
When The Chromatic Heir dies, target land you control becomes an Elemental Phoenix creature
with flying who's power and toughness are equal
to the number of +1/+1 counters on The
Chromatic Heir. It's still a land.