he's a villain who harms civillians he should get a villain ending not a respectful one
He’s not really a villain within the context of the story.
Kid is repeatedly shown as Luffy’s ally. First in sabaody and then in Wano. While he styles himself as “Luffy’s rival”, he’s never really opposed Luffy in any significant way.
Yeah he’s a violent pirate, but this is a pirate manga. WB, Roger, and Shanks all killed people. The thing with Kid is we know the context in which he kills people. He kills those who laugh at him and oppose him.
Kid doesn’t kill civilians for the sake of it.
Kid is on the side of Nika in that he supports the pirate ideal of freedom. Hence he allied with Luffy against the CDs/WG in Sabaody and against Kaido/BM in wano. With the WG and Kaido all being oppressors.
Kid on the other hand, violent as he may be, doesn’t really oppress anyone. He just crushes weaker pirates and people who laugh at him.