I Don't Understand The Appeal for Grell

Sometimes, I wonder if I'm the only one who has an extremely difficult time understanding why Grell is such a fandom favorite. Personally, I've always found characters like Grell annoying and I have no problem with people liking him, because everyone's allowed to have their favorites, but I legitimately can't even guess the reason why so many people love him so much. If you can, please give me an explanation as to why so many love Grell so much, because I do not understand why!