Sanjis limit works because he can do basiacly everything as a martial artist
Well, that's one of the reasons I liked Sanji from the get-go, his fighting style is quite interesting in the sea of sword fighters and DF users.
But I really like surprises as well. As of now we know that:
- Sanji is good with blades (but won't use them)
- his kicks are super mean, especially with CoA
- he can mysteriously produce fire & withstand heat (PoL manifestation? iirc, when Oda was asked in SBS about Sanji's fire, he said that his heart/blood burns even hotter, so his powers are fueled by feelings)
- he is so fast that he can fly
- he is so fast that he can become invisible
- his CoO is incredible, although I still wish he'd get FS
- he has improved durability & exoskeleton, and can even regenerate (not to HK levels ofc, but still)
- while not shown that often lately, but he's one of the smartest SHP
If we add CoC on top, Sanji can be legit scary.