Greenbull just casually pierced King's tough Lunarian skin with his DF that Zoro literally needed Conqueror's Haki (the strongest form of Haki) to even affect.
https://pbs.twimg.com/media/FVaNvAUXEAY227K?format=jpg&name=medium
This means Greenbull has offense at the very least on par with Advanced Conqueror's Haki users with just the power of his DF.
And he's just using vines, his superior Akainu who is likely stronger uses Magma and his fruit is considered to have the strongest offense. (Was Oda getting rid of Kaido and Big Mom in magma a foreshadowing of his power?)
And this offense comes from just Devil Fruits, if Akainu also has ACoC then damn son
https://pbs.twimg.com/media/FVaNvAUXEAY227K?format=jpg&name=medium
This means Greenbull has offense at the very least on par with Advanced Conqueror's Haki users with just the power of his DF.
And he's just using vines, his superior Akainu who is likely stronger uses Magma and his fruit is considered to have the strongest offense. (Was Oda getting rid of Kaido and Big Mom in magma a foreshadowing of his power?)
And this offense comes from just Devil Fruits, if Akainu also has ACoC then damn son
