A fight across the Multiverse (invincible oc x harem)

What if in another dimension Debbie and Nolan had another son a twin of Mark that they called Marcus

Marcus and Mark were like night and day despite the fact that they were twins they could not have been more different while Marcus was more sociable better looking and good at sports and that made Mark angry

It all came to head when Mark and Marcus got their powers. It was then when their father revealed his true intention to coming to earth about how he was part a species of conquerors and how he was there to conquer Earth

Only in this universe he didn't want to and he tried to convince his sons to help him take down the empire. Marcus agreed to this immediately however Mark had other ideas

Getting the drop on his father Mark killed Omni man and then went on a killing spray around earth killing every hero and anyone else who got on his way even his own mother

Marcus became enraged. The two of them fought constantly on the scorched earth neither one of them getting the upper hand for long until finally a portal opened sending the two of them across the Multiverse.

But their battle was far from over now they are looking for each other... To end the fight and to finally see who really is... Invincible