Luke (ルーク (ruuku, ?)) is a minor character in both Ar tonelico: Melody of Elemia and Ar tonelico Qoga: Knell of Ar Ciel, and was Krusche's former boyfriend. However, their relationship broke apart when Luke finally created an airship that could withstand passing through the Blastline, and landed in the Dragon's Nest.
In there, he met Garzbern, who among the many ancient artifacts he had, showed him a map of Ar Ciel previous to the Grathnode Inferia. With this, Luke learned that there could be other civilizations existing beyond the Sea of Death, and thus, he embarked on a journey to the region that seemed to be the most technologically advanced: Sol Cluster.
Once there, he went to the Archia Think Tank and allied himself with the Ancient Faction, which sought to restore Ar Ciel. He participated in several of the expeditions and research they conducted, which had as goal proving the plausibility of restoring the Planet. However, he also became obsessed with seeing the surface of the Planet, and thus, he tried making a vehicle capable of going below of the Sea of Death, despite the programs for its exploration being cancelled by the Think Tank, and the numerous pleads to refrain from going on this suicide mission. However, he still insisted, and eventually left for the Sea of Death. Once there, the ship vanished inside the poisonous clouds, and he died like the many others that tried exploring the Sea in vain.
The only remains of him were the toolbox that he left for Krusche, the airship he left hidden at the bottom of the Garvelt Bridge, and the records in which the Archia Think Tank declared him as deceased.