Updated with his Armed Phenomenon and indepth lore. The following theory of the non-descript timeline between Azure Striker Gunvolt 1 and Luminous Avenger iX 1 should not be considered canon.

Teseo is the last surviving member of Eden, an organization once considered an ally of Sumeragi. However, after Zonda clashed with Demerzel over control of the Butterfly Effect, Demerzel brands everyone within Eden traitors. Only Teseo was able to escape, if barely and even in cyberspace, as Demerzel had become omnipresent within the power grid and cyberspace. It was only by a sheer stroke of luck Teseo found a breach in Demerzel's domain created by another individual and escaped the megalomaniac.

The route leads him to the server of a man that lived outside the Butterfly Effect, and a man that was not welcoming to trespassers. He was inclined to delete Teseo after warning the boy that fighting him would give them both away to the Butterfly Effect. But when Teseo gives away his affiliation, the man makes a deal. He becomes Teseo's "LANlord," allowing him to use his Septima to forever reside in his physical server and out of the Effect's line of sight; and Teseo forfeits the information he's kept on Both the Sumeragi Group and Institute as well as Eden. It's not so one-sided, as the information allowed the two of them to create a catalyst for Teseo and gain his Armed Phenomenon again should he need it.