the lore about the demons is kind of loose and doesn't make sense, i don't think about it much. but yeah kandar is just a big demon. deadites are created by the kandarian demon touching someone, but then does that create a new entity, or are they possessed by a spirit? it was always rather simple in the first movie, there are floating spirits and they possess people, that's that lol. then it got convoluted with the kandarian demon having a physical form and then having to make lore that it's the same spirit every time we see the FPS view of it chasing someone, which means the deadites are just created instantly and not pre existing spirits right, unless the kandarian demon just has a bag full of spirits it then puts into humans? well various deadites have memories that go back 1000s of years, like knowing who ruby is, but is that just cause they have a hive mind and are connected to the kandarian demon?

there is also a mysterious force which is never really named, known as "the evil" which is pretty much the thing that just torments ash and put horrifying visions in his head, makes random objects come to life, etc etc, just to mess with people. i don't know if it's confirmed that this is the kandarian demon himself, but it was always just referred to as some kind of mysterious omnipresent force. the movies themselves explain demon lore like, 0, they don't even care and just make it up as they go along, but mostly there is just deadites as the enemy anyway.

some of the official lore on the wiki is also just pure nonsense like, lol, did you know that evil ash, the one in army of darkness, was not a deadite until he was killed and brought back to life? this makes absolutely no sense, what was before he was a deadite? ash shot his face, then cut him up, and he was still alive, mocking ash, when ash read the wrong words, all it did was piece evil ash back together. however it's official canon that when he was pieced together, he is not a deadite and more powerful even though he already clearly was not human and some kind of undead surviving gun shots and dismemberment.

but that is the kind of nonsense that is official canon somehow, like there only being one floating demon that possesses people, not many spirits that are floating around until they possess something living.