Avengers: Infinity War

You are the lie of Hades, the Goddess of Death - Marena.
You can summon any weapon out of thin air, but you usually fight with two katanas made of a cosmic alloy stronger than even Vibranium. You have incredibly strong regeneration and are almost impossible to kill.
You've heard news that Thanos is collecting the Infinity Stones, and now on Earth, his lieutenants are trying to retrieve the Mind Stone from the android Vision. You've been sent to help. You appear behind Wanda, as you were told, Vision's wife.