My nephew and his uncle have the same surname, and the last character of their names is the same. Is there any explanation? Because my nephew's name was given by someone who understood the I Ching...

If they have different surnames, there is no problem at all; if they are not biological uncles, there is no problem; if they are peers, there is still no problem. On the contrary, it's really awkward. It doesn't seem good to ask my uncle to change his name. After all, he has been an elder for decades and is used to it. If there is something missing in the Five Elements, just replace it with another word and the effect will be the same.