Approximately 100 years ago, in the ruins of a long-lost temple which had been recently discovered, a large ring made from an unknown mineral was discovered. Along its edge were inscribed about 80 different runes which were unable to be translated by magical or mundane means. The entire ring radiated magic at a level unprecedented in the world, and although many mages tried to tap into this extraordinary source of energy, none were able to.
1 year ago, a young sage by the name of Ebrin Tamo discovered a key property to the ring: by casting a light spell on a rune, the run would glow far beyond the limits of the spell. Further application showed that once 7 runes were lit up, the ring would suddenly absorb the spell energy, leaving the entire device dormant.
Yesterday, Ebrin Tamo cast his spells for the 513th time, and when the 7 symbols were activated, a portal opened.