Captain Dynamo was the much beloved superhero protector of Tower City. He was also a philanderer who cheated on his wife, Maddie Warner, countless times with a slew of different women. One of these women was an alien whom Dynamo met in deep space when he came to the aid of her starship, which had broken down far from her home. After aiding in their repairs, he journeyed with her crew to her home planet (the name of which has not been revealed), where he had an affair with her, resulting in a pregnancy. Because of the cultural taboo of raising a "half-breed" on her world, she journeyed to Earth after Spencer was born to leave him in Dynamo's custody. Dynamo, however, had no interest in raising Spencer or threatening his marriage, so he left Spencer in the custody of a F.L.A.G. (Foundation for Law and Government) research facility, telling them not that Spencer was his son, but that he found the infant at an alien crash site. Spencer's home for the next few years was the research compound, where scientists subjected him to extensive study and experimentation, including exposing him to the same radiation that gave Captain Dynamo his superhuman abilities, not knowing what effect it would have on Spencer. This exposure activated Spencer's shapeshifting ability, which he inherited from Dynamo. He learned how to use this power to disguise his alien appearance, and to mimic the appearance of people around him, but one of the scientists in particular, an African-American woman named Dr. Bridges, took a liking to Spencer, and the two formed a rapport. The other scientists were not amenable to how Dr. Bridges was bonding with Spencer, and separated the two. Unable to convince Captain Dynamo to remove Spencer from the facility, Bridges had Spencer use his shapeshifting ability to smuggle him out of the compound. Knowing that she would be discovered by F.L.A.G. if she attempted to raise Spencer on her own, she placed Spencer, who maintained the appearance of a full human, in the care of child services. Because of this, the two never saw each other again. Spencer spent his childhood in an orphanage, and was placed in a succession of less-than-ideal foster homes. He struck out on his own at the age of thirteen. At some point Spencer took on Dr. Bridges' last name, though when he did so is unknown. The origin of his first name, and the point in his life at which he adopted it has also not been specified.
Following Captain Dynamo's assassination, Warner, a former government agent posing as now-retired investigative reporter, discovers from his personal effects that he had been unfaithful to her countless times. Despite her devastation at this discovery, Warner realizes that without a full-time protector, Tower City would be vulnerable to Captain Dynamo’s legion of super-villain enemies. She uses her skills to track down five people who could be Dynamo’s illegitimate children. She probably found Spencer through a notation in Dynamo's black books about Dr. Bridges.Spencer was the third person Warner contacted to be on the team. He agrees to join the team only because Maddie is paying him. Gathering all five of the children together, Warner exposes them to the same unidentified radiation that gave Captain Dynamo his powers forty years earlier, unlocking their powers. Neither Warner nor Spencer's siblings know that his powers had already been thus activated, nor that he is half alien. Spencer takes on the codename Myriad, and works to protect Tower City with his newly discovered brothers and sisters.
After fighting crime alongside his siblings for less than a year, Spencer comes to trust them, but does not tell them that he is a half alien. Maddie Warner and Jennifer Chang, the mother of Spencer's brother Visionary , are taken hostage by Dynamo 5's enemies, Widowmaker, Voltage, Bonechill and Brains and Brawn, at the Aquarium, Dynamo 5's underwater headquarters. In the process of being rescued, Warner is rendered into a catatonic state, and Spencer, who tries to swim from the Aquarium to the surface, nearly drowns. In being rendered unconscious, he reverts to his true appearance, much to the shock of his siblings, who feel betrayed by his having kept his true nature a secret. Spencer sees this as hypocrisy, as all of his siblings have lied to their families about who their real father was, about their lives as superheroes, and allowed a murderer named Lionel Barstow to go free in order to free Neil Lewis, the father of Spencer's sister, Slingshot, who was being held hostage by Barstow's former employers. This argument does not convince Spencer's siblings, and as a result of both this revelation, Warner's condition, the flooding of the Aquarium, and the need to return to their civilian lives, the team seems to fall apart.
Despite this, Myriad decides to continue fighting crime in Tower City himself. He moves to a Tower City hotel, and uses his shapeshifting abilities to pose as a female masked vigilante named Vigil, relying on his natural speed, martial arts and acrobatic abilities to fight crime. When he encounters Scrap, the only other team member who decided to continue protecting Tower City, Scrap, not knowing that Vigil is her brother, decides to team up with Vigil, who poses as a native of Tower City. The two later recruit three other superheroes, Quake, and the mother-daughter team the Firebirds, into a new Dynamo 5 team. The new team suffers badly against Widowmaker, who assembles a team of supervillain mercenaries to attack them, and during this battle, Vigil is revealed to be Myriad. The team is joined by Slingshot, Scatterbrain, and Visionary, who manage to defeat their enemies. Although Quake and the elder Firebird are seriously injured, the Dynamo 5 siblings are reunited as a team.
Later after the team has reunited, it was revealed that in order compensate for the lack of offensive superhuman powers that lent themselves to combat situations that his siblings had, Spencer had been taking Flex, a street drug derived for the serum that turns humans into Whiptail, a monstrous, bipedal lizard. After he was discovered, he led his siblings and F.L.A.G. agent Augie Ford to his dealers, but agreed to stop taking the drug. He subsequently discovered, however, that his elevated strength, speed and endurance remained, which Doc Noble speculated occurred because it bonded to his extraterrestrial DNA.
The team was then attacked by their other half-sibling, Synergy, who used a weapon to erase the team's abilities and capture them. The team freed themselves, and used the weapon to restore their powers, but they manifested different abilities than the ones they previously had. Spencer found that he and his brother Gage, had switched their powers. Now possessing telepathy , Spencer took the new codename Wraith.
Wraith was one of the heroes sent by Barack Obama to confront Bomb Queen in New Port City. He scanned her mind and confirmed that Obama is the father of her unborn child.
Spencer Bridges a promiscuous womanizer in his late teens who has never held a job for more than two weeks, though he seems never seems to be without financial means. Dynamo 5 creator Jay Faerber has indicated that his shapeshifting ability will tie into his lack of direction in life, saying, "He inherited Cap's shape-shifting powers, and he can now become anyone he chooses. Maybe one day he'll figure out who he wants to be." Shortly after meeting his siblings, Spencer tells them that the people who took him and other children in did so only to receive a government check, and while he can remember all their faces, he cannot remember half their names, and feels that today he doesn't need a family. Unlike his brother Hector, who thinks of Captain Dynamo as "Dad", and has a poster of Dynamo over his bed, Spencer, who, having wondered all his life who his father was, is disappointed to learn it was Captain Dynamo, and thinks of the late superhero as "an enormous hypocrite and a horrible husband". Despite Spencer's dismissive statements about his need for family, he undergoes an eye-opening experience when Maddie Warner asks him to impersonate his brother Gage after Gage falls into a coma, in order to quell suspicion on the part of Gage's family, who are unaware of Gage's superhero life. The experience servesd to illustrate to Spencer what having a stable family is like, something he had missed all his life, but in getting carried away, he initiates a romantic overture with a schoolmate of Gage's, and when Gage, who discoveres he is capable of astral projection, witnesses the two in a romantic embrace, he sees this as an invasion of privacy, and later comes to blows with Spencer. Spencer wonders if it is motivated by racism, as the girl in question was black. Spencer apologizes to Gage, but when he confessed how having a family for a small number of days made him feel, Gage, understanding of this, forgives him. Although he initially accepts Warner's offer to join the team because she pays him, he eventually decides to move to Tower City full-time and help protect it for more altruistic reasons.
Myriad is a half human, half extraterrestrial hybrid. Although he uses his shapeshifting ability to appear human, his true appearance is that of a member of his mother's race. As such, he gray skin, no hair, and a long face that includes a pronounced brow, and a small, snout-like nose just under his eyes. The space between his nose and mouth is proportionately greater than that found in a human face, though he lacks a vertical groove on the upper lip . He also has no apparent ears, at least none that resemble those of a human. His hands have a total of three digits, including an opposable thumb, though his other two non-pollical digits are much larger than those of the human. All three of his digits have pointed claws.
Myriad has the superhuman ability to alter the form of his body, his facial features, and even the clothes he wears, in order to disguise himself as anyone he chooses. He sometimes practices his impersonations of certain people, and uses reference materials in order to perfect his disguises. Like his father, Myriad can alter the apparent size of his body, enabling him to disguise himself, for example, as an obese person. Myriad has used this ability to disguise himself as people who appear to have greater mass than he does, as when he impersonates Captain Dynamo. How he is able to do this, in light of the law of conservation of mass, has not been explained. When engaged in superheroics, Myriad does not wear a mask or helmet like his siblings, but instead disguises himself by erasing all of his facial features. How he is able to see, breathe, hear and speak without them has also not been explained. Myriad's ability to maintain a disguise is dependent upon his concentration; being punched in the face while disguised, for example, will cause that disguise to falter, and being rendered unconscious will cause him to revert to his true, alien appearance.
Myriad has also displayed considerable knowledge of martial arts and acrobatics. Although he has claimed that he has received training for it "here and there", he has relied on it considerably in hand-to-hand combat with expert combatants, in particular during his time as the vigilante Vigil. He has displayed speed, strength and agility that allows him to leap dozens of feet into the air and across rooftops, and single-handedly take on opponents such as Anchor, Chain Reaction and Blue Blaster. In his first confrontation with the assassin Widowmaker, she noted that he had some training, although she bested him and managed to escape. In their next encounter, he was able to briefly hold his own against Widowmaker and then against the physically enhanced warrior Optima, who was shocked at how his speed enabled him to evade her blows. The two villains managed to overpower Myriad together, but Myriad's remarkable speed was also remarked upon during his encounter with a villain using the Jessup-Poole strong-suit.