Sanji has used armament haki but we haven’t seen him use the black hardening version of it. He’s going to have to show it off at least once to prove he has it
How is the green smoke flames visually similar to gear 5? The green smoke is just the haki overflowing out of zoro’s body
Similar to how luffy covering himself in armament in g4 is him over using haki
Oh, if you're referring to the invisible & black Hardening, both are the same, just pretimeskip posttimeskip difference.
Not about the looks, but about how many/much a character exerts to attain that mode.
- Sanji always have CoA, he exerts Exo, then attain Ifrit.
- Luffy always have the DF, he exerts CoA, then attain G4.
Both only use 1 new element to reach G4/Ifrit, whereas Zoro requires 2 elements (the smokes & ACoC which he previously don't have)
This is based on that volume cover where Zoro & Sanji shows their power, not the inconsistency / plot-based techniques in various scenes.