Ryuboshi is one of the strongest warriors of the Neptune Army. He uses a combat technique which is based on the use of a two sword (Nitouryuu), ningyo style, which can be used underwater or even beyond.
Ryuuguu RoumonKanji: 竜宮楼門
Translation: Gate to the Dragon King Palace's Tower
Drawing his two swords, he makes a simultaneously cut able of beating a sea monster.