I've finally done a 1st sketch for the sigil, I'm enjoying a lot working on it, and researching info for this one.
As the Null faction is somewhat inspired by the Lovecraft mythos, I took some inspiration from one of my favourite Outer Gods from the mythos, Yog-Sothoth. It's one of my favourites as in I even have a plush toy of it. And I think it's kind of a rare item!
Let me explain: as I see it, the Null faction is a dark faction that is not ruled by Kings or Queens, but by Priests, that's the reason I depicted a skull with a bishop hat on it.
I also added tentacles, because the faction's God is a cosmic tentacle being.
Here's where I mix a bit of Yog-Sothoth mythology. Of course, this won't be that god per se, but it can be see as related to it. A lesser being or god, related to Yog-Sothoth, since Yog-Sothoth is father of Cthulhu and others.
The physical form of Yog-Sothoth is one of a mass of glowing orbs, with eyes or tendrils. The Null God will be a mass of tendrils with one massive eye.
For the sigil I used part of The Necronomicon Sigil, called The Gate of Yog-Sothoth (the triangle thing in the centre, the original sigil is much bigger and with more lines). And I added a flame in the centre that resemblance a little another detail from the Emblem of Arcane Protection, called The Elder Sign.
I also added some text, two "words" from two incantations, one of resurrection and another to kill the resurrected.
As Lovecraft himself encouraged others to borrow ideas from his stories and mythos, and lot of his works are public domain, I feel there's no problem with me using those ideas to add background to the Null. Like I said, The Null God won't be a god from the Lovecraft mythos, but inspired, "related" to them.
I want to add a bit more details to the sigil in a cleaner version, I feel all cosmic horror mythos are a mix of Victorian Gothic and out of earth science fiction. Hence I'd like to show the Victorian Gothic in the overall coat of arms, and the cosmic horror not from this earth in the symbol and words inside it.
Hope this all makes sense. I'm really a fangirl of all this stuff and I tend to create background info for everything :)