Nika's role in the story is to unite and liberate everyone.
Meanwhile on WorstGen, Nika and his dance has united everyone against Luffy, LOL, the irony.
Kizaru is going to do something interesting soon.
Luffy gaining Marine allies is nothing new in the story.
People will act like they're a fan of Kizaru, then get mad that he failed to murder one of his close friends. Like. OI. There's a difference between actually liking a character, and wanting a character to beat up other characters so you can brag about it on the internet.
If anything, Egghead is Kizaru's Ohara. Just like Aokiji, Kizaru is being forced to attack his old friend and an innocent child.
I don't think Kizaru can save Vegapunk at this point, but he very well might save Bonney.