The bulk update request #7257 is pending approval.
change category split_personality (155) -> invalid
Reason: This seems to be used ambiguously for a number of different things. square crossovers, conjoined characters, generic "good side and evil side" images... Some lore tagging on square crossover images that don't actually carry any implications of the character having a "split personality" based on TWYS, as well.
post #2524200 post #3811546 post #1301804
There's plural for characters inhabiting a shared body (see definition 4 of plural on Wikitionary ), which I added a better wiki for. I know plural means something else as well, but I don't think there would be a circumstance where someone would be tagging that meaning. But if necessary we could use plurality instead.
Dual_persona should probably also be included on a disambiguation page.
Updated