Indra, Nullmage of Vectis

Champion a Card (If this card is revealed as your commander, choose a non-legendary card from your
deck, it gains the supertype "Champion" and is put
into your command zone.)
Whenever you cast a Championed card, draw two
cards then discard a card. If a non-creature spell
was discarded this way, proliferate. If a creature
spell was discarded this way, return target
creature or spell to its owner's hand.