San Xing Long is one of the seven Shadow Dragons, the sixth to be fought by Goku. He is the dragon of the Three-Star Dragon Ball, and the twin brother of Si Xing Long. His elemental power relates to ice.

When faced with any threat too big for his hands, he will resort to very dirty and desperate tactics to win his fights, such as using others as a shield. He does not see anything wrong with his fighting style, claiming that there are no rules to combat beyond doing whatever is necessary to win.

Interestingly the relationship between Eis and Nuova echoes the relationship between Raditz and Kakarrot/Goku, as both Eis and Raditz are willing to fight dirty, beg for mercy, both view their respective brother's morals and honor as a weakness, and try to force their brothers to submit when they oppose their why of thinking.

(Source: Dragon Ball Wiki)