he is also sane and rational enough to admit that it is time for peace and that Ukraine cant just keep throwing bodies away for the political goals of Western elites.

That last part is your own assessment. I'm not giving Kissin credit for it. But yeah, after three years of a meatgrinder, he came to the conclusion that MAYBE this war can't go on forever. I guess a small amount of credit is due for that. Before that though, he was actively warmongering.

It might be because (I think) he said he has family in 'Ukraine', so his derangement is at least understandable.

someone who was actually deranged (like many of said elites) would never admit that Ukraine should find a way to peace even if it means the loss of the Donbas.

I think it's an Overton Window thing. The average pro-Ukraine is so deranged that they make ordinarily deranged people look sane.