[biotinker]

I of course agree that the player should not be able to overrule the GM. I don't think that was the situation here.

If you're playing an off-the-shelf campaign this is problematic. If the GM is creating the game as you go, then a good GM should be able work with the player to make this reasonable. The GM can always use GM-power to prevent a player from doing something, even if it involves a literal hand of God reaching down to stop them.

A conversation with the player beforehand to make sure you're on the same page about this sort of thing would go a long way. Let them know under what circumstances you're willing to allow them to use whatever the power is. Let them know the consequences if they don't follow those rules.

Unlike with ChatControl, a D&D game is a situation where the necessary trust is able to exist.

An example: agree the player character is some trickster djinn sent from another plane to learn to be a human and how to trick people. They have immense cosmic powers of life and death, but as part of being sent over, they can only use the power for immediate comedy. Violations result in the djinn getting yanked back to their plane and disincorporated.

Boom done. Now you have a massively OP character that can only use their power in humorous situations that don't affect the storyline, and if they try to abuse that then that's instant-death.

[joe_the_user]

I personally, as GM, don't like to be the one that kills a character. I want to set up a situation where the situation-and/or-the-rules kills the character.

I've played in games with "the GM kills you" mechanics and it felt juvenile/arbitrary/abusive. Remember, this is a game where every players' character needs to "shine" and similarly needs to know they're being judged with fairness and compassion by the GM (compassion especially along the lines of "understand what I say my character does as something reasonable").

[biotinker]

Isn't that what I proposed in my example though? Where a rule is made in advance that if the player abuses their power, they die. due to the canon situation in which that player's character existed?

A player that in good faith wanted to role play such a character, would work with the DM in advance to structure rules well-understood by all parties about exactly what would happen if they abuse their situation.

All the DnD situations can be trivially resolved by good-faith and communication on all sides.

Unlike Chat Control, where good faith cannot be assumed.