Side note, @Lyya: Drilling down via the “Troops” link by each arcane stone on the kingdom table provides a list of troops of that stone’s color, not a list of troops that use that stone. Mythics are excluded (as are hero classes, which arguably aren’t troops).
It makes sense since for example Death is not a blue/purple troops, but it does mean that to see what uses a given stone I have to go to 🔥 Troop List per Arcane Stone (Ended: 16.07.18, Reason: Lack of interests) - #73 by Tellah instead of the preferred ashtender.