Board Thread:General Discussion/@comment-27864278-20161223080945/@comment-24729606-20161224023559

My guess would that that would be either possession (if the other being influences ones actions in any way, no matter how small), multiple souls (i.e. two or more souls sharing a single physical form), or cohabitation (basically the same as multiple souls but with the possibility of interaction and possible symbiosis between the individual entities). Which one best fits is your choice to make.