Originally Posted by
Petrikow
One of the more interesting aspects of Roa is (especially in Remake) is that he seems the only person who has escaped the 'curse of immortality'. In almost every Nasu-headed work, immortality, or in the more important sense 'life beyond death' is a phenomenon that degrades your character. The amount of examples of this are so many it would almost be pointless to list them all, so let's just give Roa the microphone on this one:
Because Roa's pursuit of eternity is for the sake of his will, his directivity, Roa can continue existing (perhaps eternally) without losing his purpose. In Nasu's mind, that which renders someone 'alive' is having a will towards life. Even if you are dead in the physical sense, if your will persists, you are alive (see: Crimson Moon for the ultimate example). And despite Roa's methods, he does retain that will, even if the rest of his being (his persona, his experiences, his feelings) are continuously lost through his reincarnations, as long as Roa's will remains, he will continue being "Roa".
In a way, this is part of why Roa is such a unique villain in the Nasuverse sense. Because usually villains embody the opposite of Roa's ambitions (Goetia being a good example).
Perhaps this is why it felt appropriate that he'd become your ally in the last part of Ciel Route.