It's called the Black Sun.

I'm sorry, whenever I see that weird, jagged spiral symbol the weird Nord-obsessed people use a whole lot all of a sudden (seriously, what's it called?) I'm immediately remind of the Skrall's shields from the 2009-2010-era Bionicle stuff and Soundgarden's logo. Ironic considering the the Skrall are basically savage warrior raiders and Soundgarden's on the opposite side of the spectrum of anyone that would unironically believe anything associated with that symbol.