He would probably only be the main character for this arc. Not to mention, he'd also make for an interesting villain if he began to have conflict with the Jedi after this arc. I mean, I know it sounds slightly crazy, but IMO, it's better than having Obi-wan get transformed like some Frankenstein rip-off and nearly lose his morals, one of the main reasons I like Kenobi as a maytter of fact-his sense of justice is very strong, but now it looks like he's decideing when or when not to edge on the border of the Jedi Code.