Firaxis revealed the last of the Chimera Squad's backstories as the last of the void was filled with the Viper, Muton and former ADVENT trooper. On top of that, the story was confirmed to be canon and therefore part of the official XCOM universe.
Firaxis and 2K introduced the members of the Chimera Squad, some in groups and some on their own. You can read up on the eight previously revealed stories from our previous articles while this one will contain the stories of the last three.
Zephyr was originally one of the hybrid troopers in ADVENT's ranks. When the Skirmishers liberated her from the aliens' mind control, Zephyr quickly joined the rebel troopers and took her vengeance on the invaders. Unlike Cherub, she is not a clone, meaning she was once a human that probably had a family. Feeling alone and lost, the Reclamation gave her an anchor in the form of Chimera Squad where she is now putting her hand to hand combat skills to good use.
Axiom is Chimera Squad's brutish breacher. From that description, it is pretty obvious we are addressing the Muton in the room. He was in the invaders' army but after the occupation fell, he surrendered peacefully. Despite being imprisoned, Axiom gained respect for the humans and sought to prevent bloodshed, which led to heroics that made him Reclamation's target for recruitment.
Unlike the rest of the aliens or hybrids, Torque is not a part of the invading force that had a change of heart. First and foremost, she is technically an earthling, having been born on the planet.
After the fall of the invading forces, Torque was imprisoned and found the prison monotonous. The only way out of it turned out to be allying with the Reclamation and joining the Chimera Squad. Yup, the reason you have a delightfully sassy snek on the roster is that she was bored in prison.
The squad made of humans, hybrids and various aliens is not just a wild spin-off, as Firaxis confirmed the game is in fact canon .