Is Gear3 a mode?
Luffy also says: '' gear3: '', in addition to having several variations of attacks in this ''mode''. And that’s not why he can sustain it as a fighting style
Ashura is a demonic aura that materializes in Zoro at the peak of his fighting spirit, this is the only explanation that we have, it is totally logical that it will manifest in difficult situations, whose is not maintainable, just as Luffy did not use gear3 as a mode or the way Sanji used DJ in ennies lobby - sabaody, whose he did 3 kicks and felt side effects (is obvious that this has changed post-TS in which Sanji can use DJ regularly, freely and without prescription)
The fact that I mention HM is that it appears to be a demonic transformation, where Sanji's face appears materialized, with traces of the devil and Sanji is covered in flames, and he was never shown to be doing more than one attack in this transformation, which is why it's ridiculous to say that it's a wrestling style mode