I played Graal Online a little bit back when they had F2P. If you haven't heard of it, I think it was originally an MMO remake of A Link to the Past, and it was still blatantly based off Zelda. Anyhow, one of my favourite things about this game was that the community was terrible and everyone would be constantly trying to kil each other and steal their money. The game would lag if you went outside the bank because there's just a huge dogpile of people who came to try to kill anyone who might be making a deposit, and end up killing each other instead.
The sore loser story I have revolves around fighting fish. This was a Pokemon-esque mechanic where you catch a fish in a bottle, then you can release them and fight each other. I didn't really engage with the community and just explored it like a regular adventure game, so I just happened upon it an didn't really know how they worked.
A little while later, a guy came up to me and asked if I had just caught a fighting fish. I don't know if you can check this somehow or if he was just asking random people. Anyhow, I did, so I agreed to go fight them. We went to this area under a bridge where there's a little round pond.
We release our fish. His was a different colour than mine, which I didn't understand the significance of at the moment. But the fish fight automatically; we have no control over them. My fish manages to win, and kills his. Like, it's gone. It turns out that there's permadeath for fighting fish. My fish also levels up, which changes its colour. He had a level 2 fish and was presumably trying to find people like me to prey on.
The guy's sore loser shtick starts off with "you killed my fish..." while I'm piecing together what's going on. Of course, I had no intention of killing his fish, that's just how things work. Then he uses his fishing rod and tries to catch my fish, but it returns to me on its own. Finally, he tries to attack me - which wouldn't allow him to steal anything other than my money anyway - and I manage to kill him first. I think I had done some quest that gives you a sword upgrade.
At that time, you didn't have to respawn right away after dying, and you could still talk while dead. So for several minutes, the guy's corpse was just lying there while he tried to guilt me. "You killed my fish. It took me so long to find that fish!"