As a Marine Admiral, Akainu is one of the most powerful persons within this organizing. What is more, Akainu, as the other two Admirals, possesses one Logia Akuma no Mi, the Magu Magu no Mi, that allows him to become magma and manipulate it as his own will. This ability is very powerful and destructive, since with it, he was able to destroy the Moby Dick, seriously wounded Edward Newgate and killed Portgas D. Ace, because his ability is able to burn anything, even fire itself.
Dai FunkaKanji: 大噴火
Translation: Great Eruption
Akainu turns his right arm in a huge arm of pure magma, with which he throws a punch, capable of diverting a large attacks. This attack, at contact with an object is divided into several pieces of volcanic rock that cause great harm. Akainu killed Portgas D. Ace with this attack.
Translation: Infernal Dog
In a smaller version of "Dai Funka", Akainu turns his right arm into magma and gives it a red dog shape, able to bite the enemy. This is the attack that has given him his nickname.
Ryuusei KazanKanji: 流星火山
Translation: Volcanic Meteor
A devastating attack. Akainu turns both arms into magma. Then, he launching only the fist of each one, creating a huge volcanic meteor capable of destroying anything in his way. This attack was able to destroy Moby Dick, the Shirohige Pirate's ship.