Ok, I love it! Its so cool and well thought out. Here are some of my thoughts, if that's alright!
- I love the way that the rune designs work, its so creative!
- I got a bit confused when you mentioned mystics knowing the letters of their full name whereas other people only know their first name. I would mention before hand, perhaps in the rune crafting procedure section, that you don't know every letter right away.
- I love the though put into combining runes! Its super clever and allows for so much customization!
- I'm a bit confused on backlash. Does it just means that the more closed a rune is, the better? I guess the charts are a bit confusing to me.
Overall its super creative, and you've done really well with providing internal balance to a completely agnostic system!! I'm definitely going to keep this in mind for some of my games.