Cu Chulainn, Caster

At the beginning of your upkeep, pay {r}{g} or sacrifice Cu Chulainn.
Whenever you cast an instant or sorcery with
mana value 6 or greater, create a green 4/4
Avatar legendary creature with Trample and Vigilance named Wicker Man
Whenever you cast an instant or sorcery with
mana value 5 or less, deal damage equal to the
mana value of the casted spell.