Fukaboshi is one of the strongest warriors of the Neptune Army. He uses a combat technique known as "Ningyo Gujutsu" (Merman Weapon-Style), a ningyo fighting style based on battling with a trident. As his father, the King Neptune, he's also a "Merman Combat" master, a variant of the "Gyojin Karete", that in the same way allows the ningyos to control the water.
Kouin RyuusuisouKanji: 光陰流水槍
Translation: Spear of the Water Flow of Time
Fukaboshi spins violently his trident throwing a cut able of beating a sea monster.
Neptune gathers in both hands an enormous amount of water, then he shots a powerful wave of water against his enemies.