The teleporter leads to a secret trainer. I'm not quite sure on the exact timing, but the obelisks completely light up after a certain duration of time, which then activates the portal stone. This grants you access to the usually inaccessible location and more specifically, the trainer. He only teaches myth spells and they all exclusively focus on buffing/ affecting minions. Unless you're a Myth wizard (In which case the spells are free) they probably aren't worth your training points. Aside from spells, visiting this shop/trainer and the secret shop/trainer in Colossus Boulevard grant you the badge "Secret Shopper". Hope this helped
