Described as being selfish and closed off because of his intellect, and covetus of those relationships he does have.
He is known to have a wife, since divorced, and a beloved daughter.
Little is known about his wife, including whether she is dead or alive.
His daughter forms the basis of the Siberians projection, assuming that it is a realistic image and is not an idealized version that Manton consciously or subconsciously created, then she is relatively young, definitely post-pubescent, and possibly younger than twenty.
Manton is around middle age. His activities do not leave him much time to take care of himself  causing degradation in his appearance.
He has a tattoo on the back of each hand, on the left is an omega symbol, on the right is a stylized swan. Used to mark victims of the Simurgh and those who stood in solidarity with those same victims. Manton was never in the vicinity of a Simurgh attack.
Abilities and PowersEdit
Manton is intelligent, highly observant and a trained scientist, specializing in Parahumans and their abilities.
|Heavy Spoilers read at your own risk|
After taking a Cauldron vial, Manton is able to project an image of his daughter, though naked and striped in black and white, hence her name - the Siberian. The Siberian can ignore natural forces as she sees fit, and is effectively invulnerable. She is also able to project this invulnerability to other people by being in physical contact with them, though she is not able to make Manton himself invulnerable.
There are several other limitations. It likely takes concentrated mental effort from Manton to be able to use the Siberian, based on Grue's second hand reporting. He must remain within a few miles of the projection otherwise it will disappear, and he cannot alter or change it. Whether he can maintain the projection while he is asleep is an open question.
While on the run Manton used a car primarily to keep up with the Siberian projection, as it is far faster than any normal human on foot, and secondarily as protection, as the Siberian is seemingly unable to project her invulnerability directly onto Manton.
William is known as a famous researcher into capes, and the one for whom the Manton Effect - i.e. the inability of most parahumans to affect both living and nonliving matter - was named after.
He worked for Cauldron for some time. However, after he went through a very ugly divorce, he tried to give his daughter superpowers using one of their formulas and failed, he quit and fled with stolen formula.
| The formula William stole allowed him to become the Siberian.
His true identity was discovered through the efforts of the Undersiders and the Travelers. Though having safely followed the Nine from a distance, when his Siberian was testing Panacea his projection is confronted by the joined group and told by Tattletale that they know his secret.
He dismisses and reforms the Siberian closer to his location. While the rest of the Protectorate leaves to fight the Nine's other members, Legend and Siberian continue their battle, while Manton reveals his existence to Jack and Bonesaw before hiding with them in an Endbringer shelter. Skitter finds them and attacks the trio with a swarm on insects, grievously injuring Manton.
Manton is able to use the Siberian to save Jack and Bonesaw from the PRT's second bombing. Skitter is able to attack him as he races to save them.
He is recovered after Jack and Bonesaw return from fighting Skitter and Panacea, and is taken along with them when they deal with Cherish and leave the city with Hookwolf in tow.
Manton would rejoin Cauldron.
|Members||Alexandria • Contessa • The Clairvoyant • The Custodian • Doormaker • Eidolon • Hero • Legend • William Manton • The Number Man • Pretender • The Slug|