Uncle yukang was blocked. What are their identities?

After the king of Wu conquered the world, he was awarded the title of hero, Ji brothers and five emperors.

Uncle Yu is my son and my brother. Therefore, his enfeoffment is also called "East Ye Feng Emperor". There is also a little story. One day, Wang Cheng and Yu Shu were playing games. Wang Cheng cut a piece of tung leaf into a raft and gave it to Yu Shu, saying, "Use this to seal you." So Wei Shi asked to choose an auspicious day for Yu Shu to be his vassal. As a king, Tang was named Jin because of its water.

Kang Shu, the ninth son of Zhou Wenwang, was named Guo Kang (now northwest of Yuzhou, Henan). After Zhou Chengwang acceded to the throne, Kang Shu took part in quelling the rebellion in the Three Prisons, changed his seal to sing in the old capital of Yin and Shang Dynasties, established the country and became the first monarch of the country.