After lurking on rationalist discord servers I discovered that the Rationalist existential-risk-themed Burning Man camp was also called "Black Lotus", which is apparently a reference to an overpowered MtG card. (side note: theming your Burning Man camp on existential risk sounds like a bad trip waiting to happen)
Anyways I think the Black Lotus camp might have been the one that Brent Dill tried to bring an underage student to, as referenced below:
https://rationality.org/resources/updates/2019/cfars-mistakes-regarding-brent