What do dark Gryffindor primaries look like?
Easy. Dark Gryffindor Primaries are zealots. “The ends justify the means” is a VERY Gryffindor primary thing to say. And since they’re working on an impulse that’s coming from within - that feels right to them - they’re even more dangerous than Ravenclaws, who can at least be talked down.
Of all the primaries, a Gryff is the one who is most comfortable (and strongest) standing alone. Which means they can live in an echo chamber, not caring about other people, not listening to critics, because they are so sure that in the end... those people will understand.
This is where you’ll get a Magneto, or a Ozymandias, a Kodos the Executioner, or even a King Joffrey. Albus Dumbledore can absolutely be seen as a Dark Gryffindor, neglecting his disabled sister, controlling Snape, sacrificing Harry, all in service of the Greater Good. (Honestly, the guy *really* has Gellert Grindelwald to thank, for making him realize he’s not to be trusted with power.)
These guys feel more than they think, and they believe in what they feel. And it can make them so inspiring, or so terrifying.