The Season 7 patch changed many systems, runes being one of them. However, one particular rune seems to have avoided one change intended for it. And with that non-change, it is now a great way to get some easier rare and legendary conversions!
Magic or Rare? Yes.
The Season of Witchcraft patch changed some rune rarities to go with their tuned powers. Qua runes were downgraded to Magic AKA blue quality. However, as originally spotted by LurkerOnTheInternet, while you can see that change in-game visually, it was not applied to the actual behind-the-scenes stat.
This means Qua now drops from sources of Magic runes and are easier to get, but when you go to reforge them, they still count as rares. This means that you’ll always get a rare rune when reforging Qua, and have a 15% chance at a legendary as well!
So if you have a bunch of Qua runes laying around and don’t need them, it’s time to reforge!