C'deth Lan'Dra M'th'ra (Suh-Deth Lan-uh-da-ra Muh-thu-ra) is from the Quanta known as the Damnation Quanta. This Quanta is quite difficult to access, it's 12 Quantums away from what is coloqiually known as 'Homeline'. It has a (very undeserved) reputation as a hellish Quanta that are the home of the 'Daemonspawn', a race of creatures who infiltrate and destroy other Quanta for fun. No force or scout has ever survived invading, or even returned from this Quanta.
Of course, the truth is far less, and far different. The Quanta of Sathara is a quiet Quanta, and the Sarthan's are highly advanced, and very peaceful. Their Quanta is however a much different Quanta than most, the physical rules of the Quanta are radically different than other Quanta, especially the physical properties of the Quantum Sheath that surround it. Devices which work to breach the Sheath from other dimensions do not work to breach the way back, and the Sathara do not send invaders back, they instead place them on a world in their Quanta, in the case of an invading army, or allow them to live their lives with the Sathara themselves. When the Sathara have criminals, they exile them from the Quanta, which doesn't help their reputation, since most Satharan who are encountered are vicious criminals.
C'deth was a young physician in training. While they C'deth themselves are not immortal, because they can take on the form of any other living being, age is somewhat meaningless, as they make a habit of taking on the form of other species who can adjust their biological age, effectively making them immortal by proxy. Unfortunately, this means that young Satharan's have trouble finding a place in society, since older Sathara only leave the work force by accident or misadventure.
C'deth, being somewhat enamored of non-Satharan, had made friends with out-Quantums. Among them was a young out-Quantum human from a 5th-degree separation Quanta (between Homeline and Sathar). This out-Quantum had a natural ability to travel via Quanta. After two or three years, the out-Quantum had adapted to Sathar's sheath, and was able to leave. They offered to take C'deth with them, and the young physician agreed.
Unfortunately, the young out-Quantum had not adapted enough to leave and take someone with them, and they got separated on the trip, with C'deth being flung far from the 5th Quantum realm his companion was targeting, and landing instead in Homeline.
Infinity detected his arrival, and at first thought of him as a threat. However, once they realized he was not a threat, they instead recruited him. They keep this quiet, and on a strict need to know only, as the reputation amongst the Quanta-verse about Satharans is well known.
