Phantom

I know, this is years and years old by now, but I just re-watched the episode recently and something occurred to me that I'd never thought of before.

Danny's future self came back in time 10 years using Clockwork's medallion. How did he stay in the past?

a) He is just that powerful, he stayed there on his own, and once the timeline was changed he remained "out of time".

b) He infused the medallion into his body like he did to his younger self (so that his younger self would be stuck in the future while he made sure things would happen the way they happened). He's powerful enough so that he could get it out of his body when he needs to, but now that his timeline has changed, he is leaving it inside his body so that he can continue to exist, and thus is "out of time", since Clockwork's powers will have no effect on him while he has the medallion. Now, should the medallion ever be removed, evil Phantom will cease to exist...

c) Something else that I'm not thinking of?

So yeah, I want your opinion. Is he using a medallion to remain in existence, or is it just a paradox because he was in the past when his timeline was changed?