The Winged Dragon Of Ra

Flying, Indestructible, Riot, Menace & Offering
If you sacrifice your commanders for Offering,
their commander tax is not increased.
When this creature enters the battlefield each opponent must sacrifice a creature, Non-basic
land, artifact, enchantment & a Plainswalker.
If you control a commander this also gains
Vigilance, Battle Cry & Loyalty 3.