The Legend of Arena is a mythic Legendary Enchantment — Saga card from 2018 Heroes of the Realm (PH18), collector number 4†.
The Legend of Arena can be your commander. I, II — Create a 2/1 red Human Wizard creature token. Spells you cast this turn cost {1} less to cast for each Wizard you control. III — Search your library for a planeswalker card, put it onto the battlefield, then shuffle your library. It enters with an additional loyalty counter on it for each Wizard you control.