Seira, The Unstoppable

Constellation —Whenever Seira or another
enchantment enters the battlefield under your
control, create a nonlegendary token copy of
Seira, the Unstoppable. Nonlegendary Seiras
entering the battlefield don't cause this ability to
trigger.
Seira's power is equal the number of creatures
you control named Seira, the Unstoppable.