Damian feels unwanted, unloved. Damian wasn't cared for like his brothers. He wasn't loved by any. He was unwanted by his father, he hadn't chosen Damian. Always Getting a verbal smack-down from Tim, ignored by Jason, getting disappointed looks from dick. As he slowly dies he was left for dead at a mission and was forgotten but only to saved by an unexpected surprise. Months later with no memory of everything he joined forces with.... Harley Quinn. Because every Joke needs a.....Punchline.

Note: while Damian is Punchline, Tim is back as Robin.