Yin-yang is a amalgamation of two characthers: Yin and yang. The two halves have vastly diffrent personalities that contradict eachother. They share one body and are in constant disputes, even over simple tasks

Yin, the white half, is good-hearted,kind,honorable and rational, whose intent to balance out yang, the black half, who is massively malicious and immoral. They are both oppisites from eachother. They're both boys AND are brothers.
They sometimes hate eachother but they care about them 