in general i dont think fandom tattoos are a bad idea but i think u need to at least give yourself like a two year buffer from the end of that piece of media before you commit. like if someone told me "yeah im obsessed with hazbin hotel rn so im gonna get a hazbin hotel tattoo" id be like woah okay maybe put a pin in that idea for later. but if someone told me "yeah i read homestuck in its prime and i still love it so im gonna get a homestuck tattoo" id be like well fair enough its been like eight years. if you still like it now you'll probably still have fond memories of it in 20 years. you do you.
I'm putting this in the main post because I cannot agree more. STOP GETTING TATS BEFORE THE MEDIA PIECE HAS ENDED. Even if you can emotionally separate a bad ending or a poorly written character death from the rest of the show a tattoo wouldn't always reflect that. WAIT TIL THE END!