To take down the endurance beast, Kaido, Luffy showed off G5's maximum AP, Bajrang Gun.
To take down the speed demon, Kizaru, Luffy should show off G5's maximum speed.
Bajrang Gun was obviously a direct upgrade of King Kong Gun. It was even shown having the G4-like property of Luffy pulling his fist into himself to increase its elastic potential energy. So Nika's speed-oriented ultimate will likely bd a direct upgrade to King Cobra and focus on the Snakeman properties of being able to freely change the direction of the punch and also have the punch accelerate every time it changes direction.
When G5 is about to run out, Luffy will need to land one last powerful blow to finish off Kizaru, so he will pull out this speed-oriented finisher (maybe called Naga Gun or something else that's Hindu and snake themed). Kizaru, knowing he'll lose if this lands, will use his light speed to try and outrun it. Because the punch accelerates every time it changes direction, Naga Gun will gradually begin to catch up with Kizaru. After chasing Kizaru around for a while, the punch will finally land and KO Kizaru right before G5 gasses out. The end result will hopefully look something like this:
I think it'd be cool if Oda ended the fight like this instead of having another generic beam struggle.
To take down the speed demon, Kizaru, Luffy should show off G5's maximum speed.
Bajrang Gun was obviously a direct upgrade of King Kong Gun. It was even shown having the G4-like property of Luffy pulling his fist into himself to increase its elastic potential energy. So Nika's speed-oriented ultimate will likely bd a direct upgrade to King Cobra and focus on the Snakeman properties of being able to freely change the direction of the punch and also have the punch accelerate every time it changes direction.
When G5 is about to run out, Luffy will need to land one last powerful blow to finish off Kizaru, so he will pull out this speed-oriented finisher (maybe called Naga Gun or something else that's Hindu and snake themed). Kizaru, knowing he'll lose if this lands, will use his light speed to try and outrun it. Because the punch accelerates every time it changes direction, Naga Gun will gradually begin to catch up with Kizaru. After chasing Kizaru around for a while, the punch will finally land and KO Kizaru right before G5 gasses out. The end result will hopefully look something like this:
I think it'd be cool if Oda ended the fight like this instead of having another generic beam struggle.

