Go with these items, your weapon and 100 smoldering coal (T8 coal) to the The Infernal Forge of Ages in Solusek's Eye (Zone is at ( -69, -627, -123 ) Copy/waypoint -69, -627, -123 in Sol Eye (sub level 7)). Inside you'll find a recipe next to the forge (Knowledge of Honing the Dragon's Temper). Scribe it and create your mythical weapon. The level 2 recipe is Honing the Dragon's Temper.