Viktor doesn't reply, though his knit eyebrows and downturned mouth likely say more than his words could. He wants this thing gone--though of course there's going to be a price to pay, regardless. It doesn't surprise him that Jayce asks to take over, given his reaction to the thing inside the glass.

He wants to argue--wants to tell him that he can certainly take more of this, but maybe Jayce is right. After a moment, he relents.

"Only if you agree to switch back when you get tired again." He won't be arguing this point. "We can take turns."