These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Fan Dumb: An in-universe example. Much of DMC's fanbase is depicted as dimwitted, violent and gullible, believing that Krauser II is a real person instead of a stage persona and often picking fights with other people. They're often the instigator of whatever wacky shenanigans happen in a particular chapter.
Fanon: The entire story of Krauser II's life, as well as his various "special techniques", are made up by his fans. Often on the spot when he does something new and interesting.
So Bad, It's Good: In The Movie in after the climactic Cluster F-Bomb battle with Jack ill Dark, Negishi realizes that his crush Yuri is in the audience. So instead of playing one of his DMC songs, he plays one of his ultra-saccharine songs: "Amai Koibito" (Sweet Lover). As Krauser. The entire audience cringes in pain throughout the entire performance. One of his fans comes to the conclusion that this must be a demon's love song and proceeds to cheer for him.
And the lyrics... oh god the lyrics. Every band is guilty of horrible lyrics either put through a translator or intentionally so badly written as to give you an aneurysm.