So after some consideration, regarding MC's circumstances, Tanos surprise at him being ordinary and lore from Ella, it's possible that no one is aware that MC connects to an Arbiter, including the Apostles. At first, I thought that the Apostles in the 3rd Evolution scene were just silent in deference to the Arbiter, but it's possible that they were just catatonic/sleeping.
Also considering the Colossi, it's possible that they are direct creations of the arbiters. This idea comes from Deadend37 where Goliath talks to the Eye with such reverence, while the rest of the monsters don't even register the presence of a true god.
Regarding the various deities, it seems that my interpretation was correct all along (though I was mistaken regarding the relative power of the Ocean), I still believe that the deities who lend their power to the Big Trio are at the Arbiters' level, stronger than the Apostles and all the various minor deities. This is due to the Eye's surprise in Deadend43, as I can't find a good reason why it would care if they were powered by some random minor deity.
Once again, the Lord of Dark seems to be an enigma, despite all the info pointing to him being the 7th. Both Aglaecwif and Ella make a distinction between Apostles and the Lord of Dark. It's possible that they don't know it's nature, but it's also possible that it's something else and not the 7th. I know that I'm kinda beating a dead horse here, but still something doesn't sit well with me. Deadend3 is still a mystery to me and despite some good interpretations, I can't find a good reason why the 7th would kill MC in one instance and attempt to recruit him in another. It seems to me that Apostles don't experience the world in a linear fashion like mortals do so any simple explanation falls a bit short in my eyes.
