What is Kyle?

I'm not sure what these creatures are exactly. Everytime I think I've got them figured out, new pieces of information are revealed that ends up contradicting my initial theory. Now these things are referring to themselves as "saints," which makes me believe that they might be angels with a twisted agenda.

Might it, being labeled an outcast, have something to do with how the community responded to him after the issues 1st with his mom then his wife

maybe he is some kind of Kal-El kind of outcast, sent out by his other-dimensional/planet mother to be saved from his world. Sydney did say they could't live anymore where they're from, so Kyle-El may have been sent illegaly or by other means to the earth plane/realm/universe/dimension. And that makes him a pariah but also a beacon, cause' he was born human after all(not like the rest who have to posses other humans)

I read the latest edition of the comic and in that continuity (which has several plot and side character differences, but so far no noticeable differences in concept), Kyle is still captured.

There is a long conversation between Sidney and Kyle. As I understand it, the Outcasts have something in them from the realm where the "demons" (I'll just use this word for convenience) come from.

Whatever this was, it was hated by the demons and expelled from their home (which sounds to me like either a supernatural realm or another dimension radically different from what we'd consider physical in the conventional sense) and came to our world.

It became part of certain humans, who are the Outcasts and are needed as guides and in some cases a kind of energy source as the demons invade and take over people.

I'm going with the angel or zephilum theory. Maybe Kyle is different because HE'S the one who is actually a demon/fallen angel, hence the label "Outcast". Sydney said "we land where we land" and told Kyle they were both from the same place.

My son and I watch it together and he's thinking "aliens" from another planet.

The could be aliens and The Doctor is going to arrive in his Tardis and send them packing.

Just my two cents, but I don't think they are Demons in the way we are introduced to them as Demons. When Rev is watching old tapes it is clear that they are playing along w/ the Demon/exorcist shtick after the fact. I don't think their aliens in the conventional sense either, as in from another planet. Perhaps our idea of what a Demon is was inspired by them, whatever they are. I've not read the graphic novel, but I've seen all the episodes and think they're from outside our reality, other dimensional beings.

I do get more of a n 'Invasion of the Bodysnatchers' feel from it, which is likely where they're going with the story. I don't understand what Kyle is exactly, but obviously he's from the same place, just different for whatever reason. But I dig it!

I'm thinking: an alternative universe with slightly different laws of physics and some serious problems - so serious that they have to get out.

And Kyle could be a descendant of the first experimental cross-over - a guy who went native and had an accidental of intentional ability to send the "alties" back.