"How can you say this? They don't know what they're doing. We've done the impossible. If anyone can learn the intricacies of it--learn to weild those magics--we can do it."

It's not arrogance, from his point of view. It's fact. Viktor is, perhaps, riding a little high on their success. He's literally eliminated his own terminal illness. and even with the Hexcore destroyed, his mind is buzzing with possibilities. He can't stop here--there's so much unfinished, and without an understanding of the summoning ritual and their existence in this place, they're fully at risk of vanishing without warning, like so many others. Jayce says it himself, what that means. Returning to the exact same moment, with no memory of their time here. No memory of their time together.

If Viktor can change that, he'll do it without a second thought.

"We have to learn how it works, and change it if we can. Otherwise, we'll just be at the mercy of the Singularity--sent back at any time, without warning. Then, all of this will be just a dream."

Maybe it already is. He's painfully aware that it's the unique circumstances of this world that allows them to be together--even moreso, now that they've cured him. He lets Jayce ease him back down onto the bed, but there's still fervency in his voice. A desperation, to make Jayce understand that this isn't Viktor giving them up or destroying everything they have. It's insurance, against the worst.

"This is for us, Jayce."