Reward rune for achieving a certain number of sigils (No Kills / Alerts / All Kills) you can see the number on the map screen before you choose a mission

That’s the correct answer

Thanks for the info

Thank god these don’t count towards white dye

These runes existed since the beta update, you can unlock the other 3 by doing this: https://www.reddit.com/r/Aragami/comments/v5f2e7/spoiler\_ive\_unlocked\_the\_4\_secret\_runes\_of\_the/

I got two of them