Delta is simply put, a psychopath. She has the ability to break the fourth wall and speak directly to the player themselves. She has fun in what she does due to the knowledge that she can't die permanently. Her mind is corrupted by her power and she mostly always speaks in a happy or jokey tone. She acts as the game's main antagonist, but the player can change this based on their decisions.

She's a god among mortals and she toys with this a lot.

Warning, there is a part in this role where you'll be required to sing "We'll meet again" by Vera Lynn.