(Important Notice: I was able to perform a successful brain scan on Lorelai, whoever the data was formatted very differently than the others, so I was only able to decode a small portion of it.)
Lorelai is one of three people to appear from the Crimson Gateway near the Eiffel Tower. She showed up alongside Tosc and Gokool, although there appears to be no connection between them.
Prior to arriving at the server, Lorelai was a player of ISEKIT, a Dive Massively Multiplayer Online Role Playing Game (DMMO-RPG). Dive games fully immerses players into the game-world via a Neural Nano-Interface (NNI), also known as “Dive-Gear.”
In ISEKIT she lived in the Great Tomb of Nazarick, and was their guild leader. Eventually however after 12 years the game shut down, however, when it did, Lorelai didn't disconnect and instead found herself more immersed within the game than before, and the NPCs within Nazarick also became much more life-like as well.
Whilst admiring the stars outside Nazarick, she was suddenly transported to a black void in front of a Crimson Gateway, where she was stripped of all of her inventory. Interestingly, unlike the other two who appeared from the Eiffel Tower Gateway, she didn't stumble upon a Crimson Gateway of her own accord, as though she was teleported to it manually.
Months after joining the server, she went on to join the ADA during the Darkness' takeover of the server. She was tied for 3rd place in the Golden Blade Vote
Additional Notes: