Wait so what’s the point of Kenjaku?

Now that the stories about to end I have a genuine question. Let’s just assume that Kenny isn’t coming back and will not have any plot relevance going forward. From a narrative perspective, what does the story gain by killing Geto and having Kenjaku steal his body? The whole Kenjaku/Yuji relationship probably isn’t going to be expanded upon so genuinely what was the point of Kenjaku’s character? He’s literally just Geto but with a weaker motivation now that he's dead. idk maybe something crazy will happen in the last few chapters? Gege???