I got the genesis of the apostles right, yay xD Even if for now is only an assumption. The only additional passage in my theory is that god = origin.1) The 12 Apostles are all siblings. They're 6 sets of twins. Each twin is closely linked to each other and have half of an original trait, that belongs to an Arbiter/Origin. There's 6 Arbiters.
1st (Authority) + 2nd (Power) = Order
3rd (Body) + 4th (Memory) = Evolution
5th (Time) + 6th (Ether) = Infinity
7th (Dark) + 8th (Light) = Unknown
9th (Truth/Reality) + 10th (Dream/Illusion) = Unknown
11th (Destruction) + 12th (Creation) = Unknown.
Beyond that we don't know but the new assumption is the 6 Arbiters are two sets of triplets who's three Original traits come from one of the Outer Twin each. This is speculation though so you don't have to worry about this bit.
Just so you know. The implied position is:
0. God ???
1. Outer Twins (2)
2. 6 Arbiters
3. 12 Apostles
4. The Chosen
2) Ella was turned by, and is the chosen of the 3rd but presumably had enough compatibility with the 4th. She's like MC, but worse I suppose. I still think if she just killed Christie like she supposed to do, she would've unlocked the Memory trait. That's my own belief though so you don't really have to keep it in mind.
3) Tanos is the "son" of the Rebis, who's a chosen of the 12th Apostle. As in, that's his monster parent. We learn this from Devana and Shen among others. Tanos also called Deryl "brother" indicating that he was also turned by it. His human dad is Xanthe.
I suppose the other 6 apostles' powers are assumptions, but they make absolute sense. We know Eishtet is the daughter of the ninth and her power is all about reality. We also know that Tiffany is the fake spawn of the eight (being the other with the sixth that can travel the cosmos in an instant) and well, that's a clear connection. And we know what powers are those of the Moon twins. And that the descendants of the seventh follow the dark god.
My original assumption was based on the fact that light = power because light is a type of radiation, similar to the power of Michael in a sense, just another interpretation of it; time can equal destruction and ether (space) could bring to life or transfer things around the cosmos. Still, your theory is more grounded because it takes account of Eishtet and Evana said she creates things when talking about her monsters, so it didn't make perfect sense with the Ether and was the weak point of my theory.
That Tanos was created by Rebis itself we know from the man himself I believe, but I had another interpretation of chosen, that's why I was confused about the term.
Thanks for the answer