Luffy zoro and sanji all learned haki during the timeskip. Tho in this case ima just focus on armament in which each came out of it a different level of mastery
All 3:
Are always using haki in combat situations just like everyone else with haki. With basic observation and armament haki being invisible they’re no visual indicators really but at the same time duh. Like all 3 obviously used haki against the pacifista right out of the gate. They don’t need to say it every time
Luffy:
On top of the basic invisible armament Luffy also learned hardening. His usage of hardening being the most casual and easy out of the 3. It being enough of a big deal for him to add a new naming scheme to his old attacks like saying when he’s using hardening in base, jet -> hawk, gigant -> elephant, and Gigant jet -> roc
Also thanks to his armament he also developed gear 4 a form that relies on it. With him being able to perfectly infuse his hardening and devil fruit in order to keep his rubbery properties while having it up. The flame pattern likely insinuating that perfect fusion between the two
Zoro:
Due to being a weapons user when learning how to fully utilize armament haki he has to jump to the more advanced application in emissions. That being because to use haki on your weapons you just straight up need to learn it. While zoro did use haki against daz while in a life or death situation it was only during his training with mihawk that he actually mastered the ability enough to be able to always use it
Zoro like luffy also learned hardening. In his case him being able to use it was made to seem like a special moment. Him likely not being able to use it as freely as luffy at that point but still capable of using it regardless. Tho through his growth in wano it has become an extremely casual thing for him now. In general weapon users being able to harden their weapons is lowkey made to seem like a pretty big deal or achievement. Just looking at mihawk to zoro and oden to his retainers
Zoro also learned new enhanced versions of his old attacks like lion song -> death lion song, Rashomon -> restful paradise Rashomon, and onigiri -> purgatory onigiri. Since he’s capable of using both the old and new versions with haki (even hardening) I don’t think the new versions of the attack have anything to do with haki. Imo it might have something to do with his mastery of shusui and his scar in some way
Sanji:
Honestly his hardening usuage is a lot more annoying to pinpoint not only because most of his attacks are straight up mistranslated but oda doesn’t help really by giving much of a visual indication. So ima just go through all his variations of attacks to try to make it easier to understand
Im pretty sure we all know at least that sanji's "normal" attacks are based on just where hes specifically hitting someone. For example the attack ima show off collier = neck
Collier mistakenly translated to collier coup but is just the most basic version
Collier shoot a stronger version of the normal collier kick translated as collier coup
Collier shoot + diable jambe. He doesn't really change the name just does it with dj again translated to coup. He could also be stacking invisible armament on top of it post timeskip but that doesn’t really change the name either
Collier strike an even more powerful version of collier shoot. In my opinion the strike attacks definitely indicate armament being used but more than just him using armament it’s because he’s able to heat up his leg even further due to the added durability which is why he changes the name
So Basically
- Collier and most his basic body part named attacks are his weakest and usually used to combo into eachother ending with a special kick by the end
- < shoot versions are attacks specifically made to do as much damage as he can to that specific body part
- < diable jambe + shoot the same as before just with the dj boost. He could also stack armament on it
- < diable jambe strike a new thing post timeskip even stronger shoot. The name finally changing because he’s not just using armament haki and diable jambe but enhancing the heat of his flame with it
