In one story, Arwen had been replaced by Child!Arwen, a Sue who warped Elrond way out of character. They found the original Arwen imprisoned in a nonexistant room on the other side of the plot hole that had allowed Elrond to sip constantly from a glass of wine without ever refilling it. So all you need is to find a plot hole, and the other side could be the prison of the original Legolas and Obi-Wan.

I'd say he has to be one character or the other, but brainwashed to think he's both. So, the solution would be neuralyzation and fetching the other character from a plothole. If it's a very extreme case, such that you'd be wiping his entire memory or something, then you'd probably have to take him to FicPsych to get his personality back. I bet they keep them on file.

~Neshomeh

I'd imagine that they would. It seems like you could get a lot of good material out of that too.

"I never knew human bodies were so disgusting. Do you know how often they urinate? A lot!"