Listen, I agree that Franky could do it…but there’s a world of difference between COULD and SHOULD. Once he builds Pluton, what happens? He suddenly knows how to operate it skillfully enough to only obliterate Onigashima? I feel like there are too many X-factors there, and Franky’s a moral guy, he’s not gonna put the citizens of mainland Wano in greater peril than they already are.