Confirmed as of [Editing] this post: Aeon Master (new), "Super Sonic" Progeny, Voidsoul (Writhe's shadowy symbiote thing), Sanction (celestial tribunal)
Speculative:
Galactra - It's a no brainer that we will see Galactra as one of the scions. She references having knowledge that Captain Cosmic and his brother got their powers from Oblivion Shards and seems to weild an almost identical power as them in a different shade of color. Given all three have strong ties to OblivAeon and Galactra calling Cap Cos an "imposter", I'm betting the farm that we will see her in the final battle to come.
Empyreon - As a cosmic powered individual with EON at the end of its name, Empyreon makes a lot of sense as being a scion. What sells me more on this idea however is that Empyreon shows up in Cosmic Concurrence #15. Cosmic Concurrence #1 is all about Omnitron II. Cosmic Concurrence is also the book that gives us the comic Scions Aid. It seems to me that the Cosmic Concurrence book has a ton of OblivAeon related material so his apperance in the book certainly catches my eye. We see OblivAeon's hand on Cap Cos's incap art, so having two minor nemesis targets for Cap be Scions of OblivAeon doesn't seem to far fetched either as they are all pretty closely related.
- It's worth mentioning that Greezer is in Cosmic Concurrence for a few issues from #13-18 as well but I am not keen on him being a scion as I am Empyreon. I really feel Greezer is a "B Storyline" in the comic, a side piece of comedy while bigger stuff is going on. Consider that Deadline is also quoted in Cosmic Concurrence #13-18 as well. What do you suppose is the main storyline between those two right? But the Cosmic Concurrence book does bring us some other good guessing material. For instance, we have...
Rahazar - Who is this guy? No idea. But he has two big things going for him to put him in the potential scion catagory. The first is his apperance in Cosmic Concurrence #14. The second one that ties this together is that, somehow for some reason, his nemesis is Parse. Recall that Parse got her powers basically from OblivAeon when it created Omnitron II, and that the same exact thing happened to her a 2nd time to send her into the Fuge State promo territory. Both are direct connections to OblivAeon. Rahazar, given that context, really interests me as a scion.
Ruin - Now that we sorta know a little bit more about The Void, it's importance to the OblivAeon story, and it's connection to Argent Adept, I think a second look needs to be given to Ruin. I don't really have a convincing argument for why Ruin could be a scion other than his possible connection to the Void and Adept though. His quote from V5 Barons deck seems pretty rad though. He could be a being of The Void though which would give him more speculative scion clout then a lot of other guesses.

