The Lost One

Parker is the leader of this group that protects his dimensions and all other dimensions. There are two others, Peter and T.J, that protect the worlds along side him. However, when Parker finds out that T.J had been messing with a beaker that contained the essence of the most powerful foe they had faced in the past, it ends up taking over him and it's up to both Parker and Peter to go in search of "The Lost One" in order to save and all dimensions and, hopefully, also save T.J.

And, Lucas, the one who is known as "The Lost One", is just minding his own business, when all of a sudden, a random portal is opened up and two boys come out of it. One has a hoodie covering his face and the other doesn't. He's taken back by it all, confused. But soon finds out that there are other universes besides his and also learns he is the one that was chosen to be the one to help save all universes. At first, Lucas doesn't want to leave because he never met this random guy. Then when they take their hood off Lucas gets very confused from finding out something he wasn't expecting.

Lucas ends up going back through the portal with Parker and is taught to fight and use some of the gadgets that Parker has. At first, Lucas doesn't want to fight (he's a pacifist), but Parker explains that in order to defeat the evil that has taken over his friend, Lucas needs to learn to fight. So Lucas soon decides to do some training to learn how to fight and go try to defeat the evil that took over T.J.