So Luffy ran away, I guess Nika took over and left? But why?
We know that Lili and Joy Boy were close.
Is it possible Nika is attracted to Lili's Tool?
If Nika actually knew Zaza as an ally, I could see Nika wanting to destroy an imitation of Zaza being used for evil.
Nika is also the Warrior of Liberation, and Zaza was kidnapping children. By killing Zaza's MMA, the water holding the Giants kids should dissipate.
If we actually look at it logically, this Nika is acting more of a Warrior than Liberation than Luffy, as immediately after spawning in his first action was to destroy the being kidnapping Elbaph's children, IE taking their freedom away.
So far, their actions have been positive/aimed at saving the Giant Children.
If Nika remembers Lili from Joy Boy's past, it's very possible Nika has a large soft spot for Giant Children. Definitely has history with the country considering his encounters with Elbaph's War God.