Arcanum of the Order

The Arcanum of the Order is a reward from the following quests:
 * Allegiance of Flame
 * High Priest of Netherlight
 * I Am the Slayer!
 * In Defense of Dalaran
 * Into the Oculus
 * Selecting a Sixth
 * Storm Brew
 * The Demi-God's Return
 * The Fate of Hodir
 * The Fourth Horseman
 * The Imposter
 * Warriors of Light