[quote=@Dead Cruiser]
[@Sep] It shouldn't invalidate Thor if someone wanted to play him.

My idea was for Magni Thorson, Thor's oldest child and heir. Due to a potential threat against the lives of the Asgardian royal family, he and his siblings have been sent away to other worlds, under the care of Thor's allies.

Magni has been sent to live with his mother and stepfather, Storm and T'Challa, the latter of which he doesn't really get along with.

As a character I'm imagining Magni as mostly just being a young and impetuous Thor. A divine prince living in exile, and none too happy about the matter. 
[/quote]
It doesn't [i]invalidate[/i] the character (other GMs can over-rule me on this) but it does lock a popular character into a specific chain of events in order to allow a much more obscure character be written, while also locking Storm and T'Challa into certain events. If that makes sense?

IF you want to do the Impetuous Princling of Thunder why not just use Thor? Have him be at his 'Year 1' preset.