Ellie, Vengeful Hunter is a mythic Legendary Creature — Human Survivor card from Secret Lair Drop (SLD), collector number 2203. Current market price: $3.74, TCGplayer market prices via Scryfall.
Pay 2 life, Sacrifice another creature: Ellie deals 2 damage to target player and gains indestructible until end of turn. Partner—Survivors (You can have two commanders if both have this ability.)