Archmage Antonidas

When Archmage Antonidas enters the battlefield create "Aha!" red Legendary enchantment token
with: Indestructible, Hexproof, {4}, {t}: Remove
charge counter from "Aha!". "Aha!" deals 6
damage to any target.
Whenever you cast instant or sorcery spell,
put charge counter on "Aha!".