Oh, it turned out that his xylophone trend made him one of Lili's famous sentences. The xylophone trend is a euphemism for his mother's death. It comes from Lili's torture of the fake deaf-mute, and now it is mostly used to insult some people's incomprehensible and annoying behavior.
"gěng" is a typo of "gén" in network language, which means "laughing point, foreshadowing, or something with special meaning or irony".