Responses
I think it's child like it happens with DID, where one of the alts is the little one (most of the times a child), and the "old geezer" is maybe the host or the caretaker, and how they speak about each other, probably the bad mugo is younger than the other one.
I seriously don't think it's the definition of child... he call the old geezer like he's way too old so I doubt the third personality really is a child? I took it as vampire concept? like newly fresh vampire first time dealing with blood yk? old geezer would probably be like those noble old vamps, the perv is probably like veteran vamps but not like ancient and last one is fresh vamps that don't know how to control it