Since the summoner is not present in either Samsara or Lych's Lair, it will be difficult to farm for Level 6 crystaloids and legendary stones. This is in line with 7Roads/R2Games' policy of preventing players from maxing out. Level 70 equipment is the last of the equipments that player will attain. It is the end-game. There are no new equipments in sight (even in Chinese version patch 1.6, there is nothing new).
So there is absolutely no way of getting the crystaloids and legendary stones except for pure repetitive dungeon runs for about 250 days (approximately 6-9 loids a day). From time to time, I expect R2 to release some crystaloids and legendary stones for balens, but it will be far and few in between.
Welcome to end-game, and endless grinding.
P/S: I wish that R2Games never releases crystaloids and legendary stones for balens. Not even once.