Glamoril, the secret of life, was an artifact stolen from Akatosh himself, and is now held in the Labyrinthian, built by Arch-Mage Shalidor. So, what could Glamoril be? Could we acquire this one day, during a main quest, is it still there?
I think it would be cool if we acquired it in a future game, maybe use it to ressurect the player after they have sacrificed themselves to save Tamriel. If would certanly be interesting to see, the secret of life.