Ignis nodded. It had been Regis' ring, and his father's, and back and back and back to the start of the Lucis Caelum line. And it was powerful. Horribly powerful. When Prompto had nothing else to add, Ignis realized then just how little must have been explained to him about Noct's family and magic. Surely he had gotten some sort of basic explanation before he'd bound himself to Noct, but the barest of explanations wouldn't have gone into the Ring.
He'd meant to pull him aside and go over magic more, hadn't he? Ignis thought back to being on the road. There had never seemed to be a good moment for it, then Altissia had happened, and the thought of explaining anything had been too much. It wasn't fair to Prompto, ultimately, to not have been given all the information he'd needed to understand what had been going on when it came to magic and the Gods and probably a dozen other small details that Ignis could have helped with if he had just taken the time to stop and think. It had been understandable, perhaps, during Altissia, during the search for Prompto, or losing Noct. But after?
Ignis sighed. His state of mind had not been the best.
"The Ring ties the bearer to the power of the Old Kings — and the Crystal," Ignis replied, setting aside questions about Ardyn and what he had done. It would be easier to answer both of them once Prompto had more information. "I can explain it, and Noct's magic, in more depth another time if you want. I made a study of it, back in Insomnia…" Ignis shook his head. That was irrelevant, here. "There's a cost to using the Ring. To those without Royal blood, that cost is their life." Whether taken immediately or not, it was not something survivable, even if the Kings did grant someone their favor. If they didn't
He didn't need to say it. Not right then. It was difficult enough to face the rest of his story, to go on to explain what he did, knowing full well what he cost should have been. Prom might not have made the connection yet, but Ignis didn't doubt he would by the time he got to the end of it.
"You already know I ran into Ravus sometime after I got separated from you and Gladio. There's not much to add there. We managed to make it to the altar, to Lunafreya and Noctis." Ignis bowed his head, thinking about what they had found, Ravus' reaction. "When Ardyn showed up…" This was the hardest part. Ardyn, clever and manipulative. "I didn't know, then, that he had no actual intention to kill Noctis. That he needed him alive."
His throat felt tight from the memory of it, how he'd taken the Ring when he had the chance. It would be his life for Noct's, he'd hoped. A fair price.
"I knew what would happen, what the Ring would do, and I still —" He drew in a shaky breath. It had been a gamble. Ignis had had no way to know if he'd be considered worthy, but he'd been willing to do anything, even demand that Noct's forebears help him, just long enough to buy some time. He pulled his hand away from Prom and spread it flat on the table, the scar faded, but clearly real and clearly there.
Whatever it takes, I will protect him.
"I couldn't let him hurt Noct. I couldn't —" They all knew how deeply Ignis felt about Noctis. "I managed to get the ring, and I put it on." He didn't remember the confrontation with the Old Kings, if there had even been one. All he remembered was power, and burning, and when Ardyn was defeated, a last glimpse of Noctis before everything went permanently dark.
"I don't know why I didn't —" He'd never said it out loud. I don't know why I didn't die. It was too much, too impossible, to voice it. Too absolutely and completely terrifying, even sitting in the safety of their house, Noctis safe and alive, one of their dearest friends next to him. He blinked, realized his vision had gone blurry, wondered when the tears had started. He thought he had accepted the choice he'd made, come to terms with it, but giving it voice, knowing it was out in the world now, not just a deeply kept secret, shook him.
"I shouldn't have survived," he finally managed, unevenly and shakily.