Fate/Grand Order character. The White Dragon of Welsh mythology. In the greater Fate universe, Albion is known for attempting to dig their way to the Reverse Side of the World, and perished doing so. The Mage's Association built the Clock Tower over Albion's remains.
Huge spoilers below for Lostbelt no. 6: Fairy Realm of the Round Table, Avalon le Fae. Albion is the true identity of Melusine (Fairy Knight Lancelot), who was created from the dying dragon's left hand. The party has to defeat Melusine after she transforms into a black version of Albion.
