What Could Make My Character Change His Name?

[Ismale1]

So there is our world and a parallel world and my protagonist, Jack, from our world, parallel world self changes his name to Seth. For him to change his name it would need to be a life changing reason. I'm also maybe thinking him changing his name is apart of a new identity he created for himself. And this change would also go into the ending. My story is sci fi featuring parallel world hopping and there is a being called the dragon force that is a inter dimensional being and it goes into my secondary character Ann. She and my main character Jack go back in time to kill our Jack (the protagonist) before he turns into Seth, at the root. This is the end.

If you need some info on ideas I have for the story. Seth was the discoverer of an element called Imperium which started to turn people into monsters but this element was also used to make new weapons to kill them. My main character Jack goes to Seth world to get Ann by a character named Ben who knows the dragon force is coming and knows that if it fuses with Ann then she will become like a god and could destroy the multiverse. Ultimately Seth is the villain of the story.

[Old_Geezer]

I think Jack has been dosing on too much Imperium.

[atalanta]

Usually people change their names to start something, or to stop something. To get away from pursuers, by changing identities. To start a new life, such as when someone joins a religion. Saul became (St. ) Paul when he underwent what he thought was a religious experience.
Can this character have a brainstorm, visions of the future or of other worlds ?