In my opinion, we might have seen some of the more Advanced Conqueror’s Haki being used in the New World by the top powers. This Advanced Conqueror’s Haki is ability to coat your attack with elemental power.
Here’s some examples that we see so far:
1-The first example is Luffy at Fishman Island. Luffy has portrayed two elemental power so far – elephant gun with electricity and the fire pistol gun.
While the fire pistol gun was being explained that it’s because of friction, I beg to differ. When Luffy actually stretches his arm out, the fire seems to generate when he becomes static rather than during the motion. I have no explanation or seen any for the electricity generated.
2-The second example is from Sai and Chinjao. Here’s Sai’s normal attack which is just of wave energy.
However when Sai fought Chinjao, he also showed the same electricity attack similar to Chinjao when Chinjao fought Garp.
Also when Sai defeated Chinjao (in a way), Chinjao mentioned that your power has awakened, this could possibly refer to his Conqueror’s Haki then just raw power in my opinion. My image is not that clear, you might want to check the anime or the manga itself. When Luffy fought Chinjao, we do also see a white blueish lightning energy emitted.
3-When Luffy and Katakuri fought, this is similar to Luffy vs Doflamingo fight, we do see black red like lightning energy emitted on their punchs before they collided.
Doflamingo also emitted this when he unleashed his Conqueror’s Haki when young.
4-Big Mom, when she was screaming, also unleashed this black red lightning energy and on top of it, added wave energy that shattered the glass. Something similar to what Shanks did to Whitebeard’s ship. Perhaps this additional destruction energy of Conqueror’s Haki is something that both Luffy and the rest do not have yet except for Big Mom and Shanks. This additional energy might be the reason for the heaven splitting when Whitebeard clashes with Shanks.
This proves that Conqueror’s Haki is very important when you are fighting in the New World. Because we know that Armament Haki acts as a method to “remove” opponent’s Devil Fruit Power and fight with opponent raw physical strength, as though coating an invisible armor. If Armament Haki’s purpose is as such, then Conqueror’s Haki might just be the additional elemental energy coated on top of this armor which is unblockable by Armament Haki except by another Conqueror’s Haki user.
*Theory by boyplunger56
