Zoro's power up is that he will be able to refine his haki so much that he can use the same damage with his other two swords as he does with Enma.
Sanji's power up, that he will be able to use the same power of his RS without using it.
he will be invisible he will have better endurance , better speed greater fire , he will achieve that through better haki and maybe his connection to the lunarians.
Oda just gave them tools that makes them realize something about their powers. after Wano Zoro and Sanji might still have Enma and the RS but they will not necessarily need them.
those tools were more or less their training method. Luffy trained the classic way in battle and through hard work.
Sanji's power up, that he will be able to use the same power of his RS without using it.
he will be invisible he will have better endurance , better speed greater fire , he will achieve that through better haki and maybe his connection to the lunarians.
Oda just gave them tools that makes them realize something about their powers. after Wano Zoro and Sanji might still have Enma and the RS but they will not necessarily need them.
those tools were more or less their training method. Luffy trained the classic way in battle and through hard work.