Look at the Japanese version and you will know that Guo Weng's Japanese name sounds like SONASI.

Since its name has been translated into Guo Weng, the meaning of ~ Nasi ~ should be as expected.

Like Wulitou tree, its name is Russo, which means nonsense and deception in Japanese. This is the convention of Poké mon: a Poké mon will make a sound that matches that name.

And Gillidan's crying is lucky, and Happy Egg's crying is happy or something.