Okay I’m re-reading Fourth Wing for like the fifth time bc I find new info every read, but these two paragraphs in particular started to put some puzzles together….

I think that Brennan actually did die, but the only way that Naolin could bring him back was carving a rune into Brennan’s hand and siphoning the magic from the earth into Brennan. As we know from their rune lessons in Aretia, in order to make an inanimate object able to store magic you have to carve a rune into it from your own magic and then push power into it. When Naolin’s magic wasn’t enough, he possibly channeled from the Earth and turned in the process. Tairn nor Brennan have ever actually said that he died. Brennan said that saving him cost Naolin everything, and Tairn just doesn’t want to discuss him at all. Tairn has also mentioned before that his previous rider (Naolin) didn’t know his limits to prevent burnout and he wasn’t gonna let Violet do the same thing.

My second point is that when they’re trying to save Mira in OS, Sloane siphons the power from Dain to Brennan in order to give him more power to mend Mira, but she doesn’t have a rune scar afterwards. Which Violet questions. She thought Brennan got his rune scar when Naolin tried to siphon his power into Brennan, but this just confirmed that’s not where it’s from. 

We don’t know much about runes yet, but from what we know so far, it’s that runes are only made bc the user has to carve it with their magic like they’re drawing something in mid air and then you have to push power into it in order for it to “come alive”.  

p.s. It’s just a theory! 

Brennan and Naolin