Sure… lemme spoiler….@Quickleaf You mentioned something about this figure is familiar to Alma? Could I possibly do a history or arcana check to see if she can connect the dots?
Sure… lemme spoiler….
You can probe memories of your selves, Investigation, History, or Insight could work (and the choice may influence info you learn), to determine why this voice/feeling is familiar, DC 10+1 per self you have.
You are "spirit-ridden", but for now you are still in control of yourself. You can consult the ghost via internal dialogue (possibly you speak out loud). If you and the ghost come into conflict later, we can treat it like an opposed Charisma check to determine whether you maintain yourself or the ghost possesses you... kind of combining how sentient magic items work & the ghost's Possession works.