I love the sound of your cross-wired MC with incremental multiple personality disorder. As it's the core of your story - it is the ultimate "who am I?" - the only way to cut it is to write a different story. So, yeah, that's one darling not to kill.
Writing your cyclic seer will be more interesting, and more challenging, especially if it's in-POV; as you would be writing the same chapter at least twice, each iteration would need to see deeper details of the same moments to make it work.
For myself, the hardest I've done was attempt to write for an alternate audience: I wrote something that was intended to be YA, as an experiment. It turned out that getting an appropriate authorial voice that is so distinct from my natural one is extremely difficult. I would need a complete rewrite or three to make it successful.