I'm also just now realizing that one could argue that Damian and Jon have been running parallel journeys to on another since Bendis took over Superman and Glass took over Teen Titans. Jon gets stuck on Earth-3 and is exposed to one of the most twisted Earths the multiverse has to offer, and every time he tried to make it a little better for the people there, it didn't go well. But he stuck to what his parents taught him, and he never lost hope in their ideals.
Damian on the other hand has become largely disillusioned by what he's learned from father. He still adheres to the no-kill code (as does Leviathan apparently), but he think the way his father has gone about saving the world is totally broken.
And funny enough, similar to how Jon was mentally messed with by Ultraman, Damian is messed with by what some may call the Earth-0 version of Batman's opposite, Deathstroke. But the difference is Deathstroke, on some level apparently got to him, but all Ultraman did for Jon was make him miss his dad. If Damian is Leviathan, and he and Jon are gonna be the ones to ultimately have it out on the grandest of scales, then there's clues.
"I've tried it your way"
https://static.gamespot.com/uploads/...eviathan-2.jpg
Edit: would also give slightly more credibility in regards to why Bendis felt like it was cool to age up Jon. If this turns into a Civil War like thing, then you can't very well have a 10 or 11 year old leading one of the sides. You give Jon enough age to where he can lead a group of young heroes, and you give him enough time and experience stopping large scale conflicts and showing off an indomitable will as a hero to be a credible opposition to a new world order.
#WarOfTheSuperSons