I myself do not know much about TR3-VR, or Trevor. From what i can piece together, Trevor is located deep within the bowels of Tower North, and is most likely a security unit that has malfunctioned, due to no one in Tower North to sustain his systems. He has a square-shaped body and scissor like legs that chop up any guardian that is unfortunate enough to cross Trevor's path, God forbid a non-light wielder. He can easily pursue any guardian that chooses to run instead of hiding. Trevor's domain is a maze-like area, located underneath an armory/hangar type of area. To find this terrifying death roomba, you need to have access to the "Zero Hour" quest available in the basement of the hangar in the Farm, after you find all Fallen Transponders found in the Lost Sectors of the EDZ, and Nessus. Or basically, the "Outbreak Perfected" quest. when you get in the basement, a friendly Fallen Captain will give you the option to Rendezvous. If you accept, you will go to Tower North to get Outbreak Perfected, the pulse rifle. Follow through to the quest, and you will arrive at a room with a large window. Through the window seems to be jumpships and miscellaneous objects, with an occasional red light moving around. You have just entered TR3-VR's domain. Be careful Guardian