Longer than I'd intend, but the way I describe it is probably as

1. A mystical Harry Potter based sex cult deeply embedded in the techbro scene. They want what many cults want: to commune with God, achieve immortality or enlightenment, and obtain power in the current world, but they dress it in the trappings of science and computer programming.

2. Do to demographic features, their desire to be clever, and a certain contrarian attitude, they will often seek to rationalise harmful social practices, which leads them to support anti-feminist and race realist positions with shocking frequency.

3. Because of their close connections to the tech scene, along with the personal relationship the cult founder had with Peter Thiel, and the fact that the cult has been indoctrinating kids since the aughts, they are shockingly influential in the AI scene.

4. As most cults, they claim to want to teach people to think correctly (rationally), but they actually value the community of being in a cult (and the potential social networking and financial benefits) over thinking rationally.

5. In terms of style, they like long works with unclear arguments, being clever or witty over being right, and strongly signalling their rationality (sometimes even using good tools), but not allowing that to interfere with the core features of being a cultist.

(1-3) are what I'd consider core. (4-5) are what I'd add if the person seems interested. If they seem really interested, I'd also discuss other connections (e.g. to Effective Altruism, the Future of Humanity Institute, George Mason University, Future Perfect, neoreaction), their ideology in more specific terms (e.g. the Sequences, Roko's Basilisk), and associated members (e.g. EY, SSC, Aella, SBF).