Leonardo DaVinci Dufae was the designer of the inter-dimensional gate that transports Pittsburg to Elfhome. He was killed in Oakland, a neighborhood within Pittsburg, ten years before the first Startup.
Dufae was the descendant of Unbounded Brilliance, a Stone Clan Domana elf who was stranded on Earth after the natural gates between Elfhome and Earth were purposely collapsed.
Against his father's wishes, Leonardo married Wai Sze Wong, a tengu woman, but they were unable to have children naturally since they were genetically incompatible. In an attempt to reconcile with is father, he had his sperm cryogenically stored so that grandchildren and continuance of the Dufae family would be possible. After his death, his father Timothy Bell (Dufae) created Leonardo's daughter, Tinker, from Leonardo's cryogenically stored sperm. The ovum was from Esme Skenske an astronaut that was aboard the colony ship that was lost in through the gate at first Startup.
After hearing his great-aunt's stories about Guillaume Dufae, at age 10 he began working on theories that would lead to the construction of the inter-dimensional gate that transports Pittsburg to Elfhome. The family had a Codex of the family history, elf culture, and stone clan esva, which Leonardo used heavily in designing the gate.
Lord Tomawaritomo ordered Leonardo to be kidnapped to build a gate to Onihida. The oni accidentally killed Leonardo in a car accident during the kidnapping attempt.