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Although I believe that what dictates how advanced your CoC is in terms of power/intensity (not in terms of control) is how strong you generally are, if I'm wrong on this, then one possible alternative is that Imu will use Domi Reversi on Sanji and offer him a magic boost, like some posters suggested. That would unlock his full potential and allow him to use the perfected version of ACoC without having to improve his CoC gradually.