The Arcane Warrior

You encounter a phylactery inside of the Ruins. when you touch it you hear the voice of the last elven arcane warrior who has remained trapped inside of the phylactery for centuries. He offers to teach you the secrets of the Arcane Warriors in exchange for setting his spirit free by placing the phylactery on an ancient altar. While the spirit of the elf has been imprisoned for so long that it forgets where the altar is located, the anvil is actually right beside the phylactery. By destroying the phylactery, you unlock the Arcane Warrior specialization for the mage.