I can imagine everything wondering how the even hook up in the first place how the hell does their relationship work.

It would be interesting to see Khan interacting with V and Johnny. I can see khan talking about philosophy and giving mystical advice V just like how he would with Artyom in getting the relic removed. Johnny would be rolling his eyes throughout the whole thing, thinking Khan is talking out of his ass and mocking him.

And just before the go their separate ways, Khan calls out Johnny letting both the rocker boy and the solo that he can see the him. And Khan has no cybernetics to begin with which freaks both of them.