"I'll try to." Then after a pause, he amends, "I will. There are few reasons why I would let myself be locked up. I'll fight."

Though he doesn't realize it now, it's part of the reason Thanatos does not choose the option to go back in time. Doing so would trap Thanatos in a world where he cannot be anything more than Death Incarnate, where nothing changes. He choses to go home with time having passed because he's going to fight... even if it's hard and people have suffered. There has to be something better for all of them.

"I expect you to fight too. There people who need you." Thanatos looks down at the pomegranate with Mort flopped atop it. "And for reasons beyond fruit."