4a.- For those who do not know my totally unconfirmed theory- I believe that Virgil is not in his true form (yeah I know, I like the whole deception route with vampires) and he has found a way to mask himself from Calisto- not the Virgil personae but the Arcus true form which I believe he is, and who may have tried to take Calisto's life before but failed. I believe he is where he is now not only for Calisto, but empowered by her blood, then Vision Girl. Now that he has been in close proximity to the MC for a length of time, he knows who the MC is. What clinched that for me was "He would do everything in his power to find the MC's Sire". Since he wants a rematch with her now that he has a couple thousand years on him, he is betting he can take her. The MC is the VG's idea to help tip the balance in that battle. I do know that the MC is not going to be a God powered vampire, at least in this novel timeframe, but he doesn't need to be God level to help his sire against her first childe in round 2, and he might even get to kill him and drain him dry, as well as Roland, and could become Princep. That is not out of the realm of possibility, and does not place him in God level vampires yet. I do think he is a 5th generation of whatever the clan is, and so is Virgil. It might not even be a clan even, but an entirely separate bloodline after the curse or blessing from Hera for the bear form. (yes I am sticking with that). I know I am not far off the mark on Calisto's origin/age. The rest is pure conjecture.
Peace.