He's not constantly evolving Sanji already had those techniques in his arsenal from the beginning.
In east blue Sanji only knew the techniques of capoeira and Zeff's kickboxing. He didn't even name his attacks.
Then in Arlong Park, Sanji demonstrates kyusho-jitsu techniques, a set of traumatic techniques that search for pressure points that was named ''collier, épaule, côtelette, selle, poitrine, gigot and mouton shot''
In alabasta in the rain-base, Sanji shows improvement in the mouton shot technique, which is the anti-manner kick course, showing that he was improving his kicking class.
In the fight against Bon Clay, he had to develop a series of new kicks and moves, since Bon Clay was completely dominating him with the swans.
So Sanji replaces the technique: ''collier, épaule, côtelette, selle, poitrine, gigot and mouton shot'' for ''Basse Côte, Longe, Tendron, Flanchet, Quasi, Queue, Cuisseau, Jarret, and Veau Shot'' , and then he managed to balance the fight again with Mr.2 and overcome him. It was an immense progress in your battle techniques here.
In skypea, he developed the concassé, which is a spinning kick technique that increases the power of your kicks, again showing progress in your kickboxing skills
In davybackfight he developed another kickboxing technique for his arsenal of kicks, which are the hachis, starting with the troisieme hachis and bouquitiere shot.
At the Franky house, Sanji showed the party table kick course, which would be the AMKC technique in spam. Showing improvement in his kicking and movement techniques.
In the train saga, Sanji developed techniques for the barbecue nomenclature: Brochette, collier frit, frit assorties, escalope and Sentén Découpage. An immense progress in his arsenal of kicks, which demonstrated his mastery with kicks by managing to have "surgery" on Wanze's face. Besides, his fight with Wanze also showed a big up in his combat speed
In his fight against Jabura, he perfected his Troisieme Hachis technique (Third-Rate Mincemeat) for Deuxiéme Hachis (Second-Rate Mincemeat), then he unlocks the diable jambe and perfects his deusiéme hachis technique for Premier Hachis (First-Rate Mincemeat) notice how the attack nameds show an improvement in the power of kicks.
In his fight against Absalom, he perfected the premier hachis for Extra Hachis ''Highest-Rate Mincemeat'', which would be all techniques combined, again showing immense progress in his kicking techniques and being able to combine them. Then Sanji was already wearing diable jambe and showing monstrous deeds against Oars.
All this rate of progression and growth of your martial arts / kickboxing techniques, also reflects in the immense load of physical growth, both in strength, power, durability, endurance and speed. So there is a huge gap between the Sanji base of the east blue and the Sanji base of saboady.
