Which is still the weirdest thing to me, because Eye also implies that MC inherited his connection from mom, who, logically, inherited it from Momory. Which kind of makes me question body's motives in all of this.
What strikes me as weirder still, specially in regards to the tainted lineage comments is, how Eye also says it is MC and becomes more whole as time passes and sees all the bad ends.
That's not just one sphere higher, but at least two spheres because it's able to accurately discern all the weird godly shit going on at a glance.
Yeah the monster gods are all in the outer sphere. The Arbiters were just the precursors to the Apostles so they'd have been out there too. Pretty easy to infer that being more "complete" the Arbiters would also have greater awareness and influence over the universe. In those dead ends The Eye is mostly held back by it being too early for MC to bring out all its power, otherwise it seems confident that it could beat the big 3.
I don't really have anything for Body's specific motivations because we don't get as much about it as we get about Memory, but it's likely that it's just fully cooperating with Memory seeing as how it's known that the 3rd and 4th are far... friendlier? with each other than other Twin Apostles. About the inheritance of the Eye, my read on it by its own words is that it was aware of and technically connected to all branches of the spawn of the 3rd and 4th, but never truly manifested within one until it found a "perfect" host. Syla still wouldn't have been a suitable host for The Eye even if she wasn't tainted for instance. It seems very much like the 4th wanted a pure Memory Chosen as a stepping stone to get that perfect 50/50 and didn't believe Syla's child/spawn would still end up close enough after being tainted. That seems to be why the MC has been allowed to develop pretty independently from the 3rd and 4th's plans. Without knowing he was close enough, and without Ella being able to confirm he had both Apostle's traits from the start, he was allowed to do his own thing. Though in the Memory training we do see that the 3rd and 4th both value the MC
VERY HIGHLY at that point, subduing the 1st when he's on the path of Authority. So if not both Apostles, the 4th probably realized he must be protected and 3rd is particularly cooperative with its Twin (and maybe particularly hates the 1st). As to The Eye integrating more with the MC, its statement is very much that it IS the MC. The stronger he gets, the more active The Eye is. Given the dead ends it's a lie of omission, but not an outright lie. Henri is after all still Henri despite inheriting Chaos, so we know it's telling at least part of the truth.
And then there's always that Too Strong Too Early dead end to look back on with every new bit of info and perspective we get. This part is all just me throwing spaghetti at the wall. It seems very much like the 3rd and 4th wanted their perfect spawn ASAP, and the Lord of Dark is actively opposed to their plans which is why it attacks if Ella immediately confirms and brings MC to them so soon. What I'm curious about is whether the 7th is actively opposed to an Arbiter or its power showing up, or if it would be fine with MC having the power of one, and specifically wants to keep an Arbiter's power away from the Apostles given that it clearly has its own individual plans.