Mercy Pyrope

However, it wasn't until Noct officially began his quest at age 20 that Carbuncle started planning to get involved in a more major, active way. When Noct's initial party of four found their way to Galdin Quay, so did Carbuncle, in disguise as a young man around their age with bluish-green hair, calling himself Mercy Pyrope. With a craftiness that would make the Astrals proud, Mercy figured out how to insert himself into their agenda without seeming forceful or unnatural - appearing to be a regular guy who happened to be around at the right time to help them out. And so, he wormed his way into their hearts (platonically at this point) with his sweet personality and sense of humor, charming them just enough to be seen as a pleasant acquaintance - maybe even the beginning of a friend. Once seeing his miraculous abilities of healing without the use of items, the party agrees that it's worth a shot to take him along.

He makes himself useful along the way, always trying to help when help is needed, whether it's with cooking dinner, gathering supplies or lending an ear when someone needs to vent. Though, to a normal Astral, this would all be pretense, Mercy genuinely does like the guys, and sees them as his best friends after enough time passes. He's never had friends before! Not that he tells them that, not that they figure it out with how friendly but socially adept he is, but it's very exciting.

He is blissfully ignorant for much of the main plot of the Minivan AU, believing he is working for the forces of good - until the disaster in Altissia, at the summoning of Leviathan, when Ignis, running madly through the streets of Altissia to find Noct, accidentally happened upon a tidbit of cosmic wisdom he was never meant to find, from Pryna who was lying with and comforting Luna in what initially appeared to be Luna's last moments.

(Luna survives, and, of course, so does Pryna. Dogs dying is illegal. Don't be an idiot.)

Ignis learns that Noct is fated to die in order to complete his quest as ordained by the Six.

Mercy learns that the Six have lied to him - perhaps they'd call it something other than lying, and insist it was for the greater good.

Luna reveals that she knew all along, and breaks down sobbing in front of them, barely able to take this cruel prophecy any longer, realizing that perhaps Gentiana and the Six have been cruel to her from the very beginning.

So, the three of them form a pact: To do absolutely everything in their power to change Noct's fate, and find a peaceful, happy ending that doesn't result in Noct's horrible death. After this incident, the three of them become inseparable friends, all having such an important common purpose that leads them to come together in other ways, as best friends and comrades.

This secret is theirs for a long while.

Despite being an Astral, Mercy is not perfect. He has a gullible streak, tending to fall for promises of heel face turns and friendship from his adversaries very easily. Similarly, he tends to believe what he is told and rarely questions it - and thus, is unintentionally complicit in a number of horrible situations. These situations include large-scale horrible, like the prophecy involving Noct, and smaller-scale horrible, like the unhealthy friendships Gladio has with everyone in not knowing how to handle his own emotions productively. However, once he's able to put two and two together, Mercy works hard to fix the mistakes he's made as well as he possibly can. Another weakness of his is how quickly he falls in love with people - this is a beautiful thing, of course, but leads to serious trouble when he's more inclined to trust those who ought not be trusted, at least at first, such as Ardyn and Ravus.

Being such a young (for an Astral, anyway) and simple being, who has not experienced any truly severe trauma (though he ends up with his fair share of it later on in the plot), he's not predisposed to have particularly heinous or toxic flaws, but he's got 'em nonetheless.

[WORK IN PROGRESS! tl;dr witness my power move of just flat-out making an indulgent character who 2000s era fandom would bash as a "mary sue" without even the slightest bit of shame B) ]