There’s nothing special about the day Nico gives up. No grand inciting incident. Just a slightly younger version of Nico who’s tired to the bone of bending and breaking himself to fit his father’s expectations. His father makes his usual remarks about how lucky it is that Dunark has Erasmos, about how quickly Dunark would get invaded demolished turned into anarchy if Nico ever were to sit on the throne, and there’s nothing special about today except that Nico responds.
“I… I don’t think I can do it. Not ever. I can’t learn to kill.”
The scene changes. It’s a few hours later, and Nico is standing in a room every surface of which is covered in books and vials and alchemy notes. He’s just finished recounting the argument to an older man sitting at a desk. The man looks up at Nico, his face looking heavy. “Nico, kid... I know it's hard to hear, but he isn't wrong, exactly.”
Nico looks deeply hurt as he tries and fails to come up with a response, and the man continues, looking earnest and caring and deeply, deeply serious. “I'm sorry, Nico, but you're the only good person in that rotten family, the country needs you —”
“But I can't, though, that's what I'm trying to say, I can't do it, Marlin —“
“Yes you can, Nico, I know you can, you are so much stronger than you think, you just need to try —”
“I've been trying my whole life! Trying to hold my tongue when he makes those awful comments, trying to work hard at training even though the swordmaster is awful, trying to be the son my father wanted, trying to be a perfect copy of Erasmos —“
“I'm sorry, I know you're working hard, but you just need to —“
“You don't know anything! Or you wouldn't have said — you're free to sit in your tower and do whatever you fucking want, you don't know what it's like, I try so hard every fucking day and you say I need to try harder and I can't, Marlin, I fucking can't!
“Nico…” He reaches out his hand.
“No!” Nico steps back, out of reach. “You don't get to do that, you don't get to hug me and then everything's alright again, that's not how this works, you want me to try even harder when I'm already —”
Nico's voice shakes as he says, so quietly it's almost a whisper, "I don't want to try anymore." And then he turns around and leaves the room, leaving the old man looking lost.