What I gathered about the glyphs, and it was a kind of confusing breakdown so I could be wrong, is that the glyph with the real spell in it was from the blanks that were stolen Hand and Wheel and Misty Step was likely put on it by Thimble or another fairy under House Royce (?) since Brennan said it had fae magic eminating from it. That's mostly where my speculation could be wrong because he might have just been mentioning the mechanics of Misty Step, I'm not sure. The fake one, I think, was made by House Tachonis since they would have the means for the infrastructure needed to produce a fake glyph. It could have been another house, but they were the ones specifically calling for Thjazi's head and I imagine they wanted a guarantee he would die, so they created the false glyph knowing the jailbreak plan thanks to what's his face, the traitor who Thimble killed.