I hate to say this but unfortunately, we have to remove Master Xehanort from Pure Evil. He not only confirmed that he was a well intentioned extremist all along, but had a Death Equals Redemption moment where Master Eraqus' spirit puts his spirit to rest and they go to the afterlife together.
Alternatively he did suffer motive decay and ended up as a powerhungry maniac, but snapped out of it in his final moments