It is true that the image of Viktor on the other side is deeply unsettling. It's difficult to see the person he loves look so inhuman, but the discomfort comes more from the reasons why than the actual image. If this is what Viktor ends up having to do to save his life, will he go too far from who he is now? This is their nightmare though, something they are afraid of. Not what they actually are. Jayce knows he would support anything to keep Viktor alive.

He sees that it is upsetting Viktor though so he runs his hand up and down Viktor's back soothingly. "Hey, it's okay." Jayce does understand, disturbing though it may be. Hasn't he taken himself down a horrible road himself? At least for Viktor it is to save his own life, he doesn't have an innocent's blood on his hands, not like Jayce. "I would love you purple limbed and covered in runes too." That he is sure of.

"I don't know if they will, we have to be prepared for that." Meaning, they may keep whatever this thing is, and there is nothing the rest of them can do about it. For now. Jayce is focused on getting rid of it first, but the reality they could be putting this monster into their hands is legitimate.