To find Vulthuryol, access the center building area in Blackreach where there is a large yellow orb above the Blackreach Debate Hall and the Hall of Rumination. The closest exit from Blackreach to this orb is the Great Lift at Mzinchaleft.
The orb is visible upon entry. A number of Falmer and Falmer Servants will be hostile and one must thus fight their way through them. After doing so, use Unrelenting Force on the orb. Doing so will make the orb ring and echo throughout the caverns. This will summon Vulthuryol.
If the Dragonborn summons Vulthuryol and does not engage in combat with him, he will eventually take up a stationary position on the ground outside of the south entrance to the orb complex. If the Dragonborn is positioned on the ramps leading from the top exit of the Hall of Rumination or other high vantage point, Vulthuryol can be range attacked and he doesn't rise from the ground. Vulthuryol can only be summoned once.
- Unlike other dragons, Vulthuryol will not fly while fighting the Dragonborn, but will crawl on the ground, using Fire Breath.
- Although being an Ancient Dragon in its essence, Vulthuryol has a very low damage output for both shouts and bites and drops standard loot for a dragon, but he is still difficult to defeat if fought by a Dragonborn lower than level 20.
- Vulthuryol cannot be tamed using the Bend Will shout.
- Harkon's Sword is quite useful against him and makes him easy for a Dragonborn at level 10 or higher.