Summons of the Fire Demon

This spell costs {x} less to cast, X is the number
of red creatures you control. If you control three
or more legendary red creatures you may
instead cast this spell for free and it has flash.
Haste, Trample, Protection from Black and Red
+1/+1 for each red mana-producing source you
control.
"At last! Behold, our vengeance is at hand!"