I played the "time-traveling" such that its occurrence affected little in the way of the current world. Rather than having traveled directly back in time in his own world, he was switched to a different timeline [i]similar[/i] to his original's past. This means his actions in the "past" (the present of First Blood) don't do any timeline mumbo-jumbo to the world he's in. It's already been established by yourself that other worlds beyond Earth exist, so I don't understand how it [i]isn't[/i] a plot device already.

No more "overt" than villains living in the world already. I'm sure you've devised supervillains that have killed heroes before, and are still at large. If that isn't the case then the League is damn near perfect in its ability to apprehend criminals. I don't believe you intend for this Jailbreak/Hostage situation to go perfectly, and in such a case the League isn't capable of countering every evil force there is.

I don't mean to argue for the sake of arguing; I want to defend the ideas I have as best I can.