Aang, Airbending Master (Extended Art) (TLE-171) - Avatar: The Last Airbender: Eternal-Legal Foil

When Aang enters, airbend another target creature.

Whenever one or more creatures you control leave the battlefield without dying, you get an experience counter.

At the beginning of your upkeep, create a 1/1 white Ally creature token for each experience counter you have.