Die-hard

Die-hard is an internet slang term used to describe someone who is extremely passionate, dedicated, and loyal to a particular person, thing, or idea. Die-hard implies unwavering support and enthusiasm, often to the point of being extreme or obsessive.

Example 1:
In an online gaming community, a player who is a die-hard fan of a specific video game series may spend countless hours playing the game, discussing strategies with fellow players, and even creating fan art or fan fiction related to the game.

Example 2:
On social media, a die-hard follower of a popular singer might attend every concert, own all of their albums, constantly tweet about them, and defend them fiercely in any online debates.