Cyn

Similar to N, V, J, and the other Worker Drones working as servants in the manor, Cyn was also abused by James and Louisa Elliott. On the contrary, Tessa initially liked Cyn. However, over time, Tessa realized that something was off about Cyn. It is presumed that Tessa asked J to lock Cyn in the Elliott Manor basement as punishment, due to her very abnormal behavior, even though "Cyn" escaped many times.

The Solver was preparing to kill all the humans, on the night of the gala hosted by the Elliott family. Although it's unknown if she was the cause, many Worker Drones in the manor were struck with wd0S_606 (also known as Error 606), rendering them catatonic and frozen in place, including V. This caused N, who's infatuation with V was strong even back then, to read to her about dog breeds he loved, most notably golden retrievers and their gentle mouths that made them good with kids.

However, when he ran into "Cyn", she asked if he was willing to attend the gala with her despite how angry it would make Tessa's parents, as explained by N. Regardless, the AbsoluteSolver managed to convince him to ask Tessa by using Cyn's screen to show him "literal" puppy dog eyes, only for N to take the fall for her, ending up in the swamp for the crows to mangle him after the Solver had talked back to Louisa. Subsequently, Louisa bound Cyn, Tessa, and J to chains and locked them in Tessa's room. Angered over N's fate, Tessa threatened the Solver that if N, whom Tessa liked even more than J, died for her sake, there would be dire consequences, to which she reassured her that it had backups.

Suddenly, Tessa was met face-to-face with Cyn's eldritch form due to the AbsoluteSolver's presence within her. It assured Tessa that she wouldn't have to discard her "pets" and that in return, it wouldn't discard her either, warning Tessa that she should "best stay away from the gala, though." Remarking her visible nervousness, the Solver went off to the party with a well-timed giggle during James' speech on how the Elliotts were known for being alive. Tessa and J escape captivity and burst through the front doors to the ballroom, planning to execute "Cyn" before she can get away with the imminent massacre.

Tessa's attempts to stop "Cyn" were in vain, as its only response to Tessa's threats was that she "didn't have to see this" before she proceeded to slaughter every human in the room, including Tessa. Afterward, Cyn's body was grafted into Tessa's corpse, fusing the two.

What happened afterward is unknown, but after taking over the other Worker Drones that worked at the manor and converting them into Disassembly Drones, the AbsoluteSolver would send copies of them in squads to the human exoplanets for reasons undetermined. Despite choosing to keep their personalities intact, it also erased their memories of their past lives and convinced them that JCJenson created them to exterminate all Worker Drones because they were "corrupted," and Cyn disappeared from Earth afterward.