Finally understanding the meaning behind the words inscribed on his Uru mace, "The World Still Needs Heroes," Kevin Masterson no longer resents his father for being a hero and accepts his own destiny as the new Thunderstrike.
Kevin's mother, Marcy, left him and his father, Eric, at an early age, deeming herself unready for motherhood; Eric and Marcy subsequently divorced. Kevin became close with others in his father's life like his executive assistant, Susan Austin, who helped raise him; Jerry Sapristi, Eric's business partner; playmates with Jerry's daughter Maria, and looked up to construction worker Sigurd Jarlson (secretly Thor. Marcy decided to come back into Kevin's life after marrying New York Smashers’ starting quarterback, Bobby Steele, which put more of a strain on Kevin's parents' relationship; something Kevin was initially unaware.
Kevin idolized Captain America, but began carrying a toy hammer after Thor saved his father from the villainous Mongoose. When a man named "Brute" Benhurst received the armor and enchanted axe of the Executioner (Skurge), Kevin aided Thor by striking Benhurst with a plastic hammer. Benhurst went to hit Kevin, and Thor quickly defeated him. Thor then put an enchantment on Kevin's toy hammer that would allow him to summon any other hammer-bearer in time of need. Kevin was not aware of this. Mongoose returned to kidnap Eric, and Kevin unknowingly summoned Thor to rescue him. After Eric was physically merged with Thor, he introduced Kevin to the Olympian god Hercules as "Harry Cleese." Hercules revealed his true identity after moving in with the Mastersons and defended Kevin against Stellaris the Celestial Slayer.
Stuck in the Middle
Marcy was unaware Eric's bond with Thor frequently kept him from Kevin and filed a complaint with Child Services, hoping to get sole custody. Eric wanted Kevin to have a normal home life and relinquished custody of his son to Marcy and Bobby Steele. Bobby took Kevin to Disney World and introduced him to weightlifting and calisthenics, intending for Kevin to later get a football scholarship. There Kevin met Spider-Man who saved him and his mom from a freak snowstorm caused by a mutant assailant. Under the influence of the Enchantress, Susan took Kevin from school as part of a plan by Loki to ransom the boy for Thor's hammer, Mjolnir. Thor saved Kevin and left him with NYPD's Code: Blue for safekeeping. Enchantress tried to cover her involvement by compelling Susan to save Kevin and Marcy from Loki who attacked them to spite Thor. Susan was badly injured by a mystical blast and was hospitalized. Enraged, Thor seemingly killed Loki and was banished, leaving Eric to assume Thor's role and join the Avengers. Kevin would visit Susan in the hospital often, and overheard Bobby arguing with Eric about adopting Kevin.
Thor eventually returned and regained Mjolnir, but Odin had an enchanted mace created for Eric so he could become the hero Thunderstrike. Susan had become the caretaker in the Steel home, Marcy opened the Salon Steele health club, and Bobby secretly began using steroids to maintain his waning sports career. Bobby's drug use caused numerous problems including a steroid-induced rage inadvertently exposing Kevin to a rampage by the Juggernaut. Kevin faced other scares at school, including the assassination of his substitute teacher, child pornographer Mr. Gerrins, by the vigilante Sangre. Kevin convinced Bobby to get help for his steroid use, but Thunderstrike thought Kevin was in trouble and lashed out at Bobby. Kevin called Thunderstrike a bully for picking on normal humans, hurting his father's feelings. Later, a friend brought a gun to school, barely missing Kevin when it accidentally discharged, and Sangre in her civilian identity of police officer Julia Concepcion helped the boy to admit he brought the weapon because he was afraid of bullies at school; furthering Kevin's dislike for bullies. Kevin later made a deal with Mephisto disguised as a stranger to not let Bobby get transferred to a West Coast team, so he wouldn't be separated from Eric. Mephisto made Kevin comatose, but Odin healed and blessed the boy, nullifying the deal. Eric eventually revealed his secret life as Thunderstrike to Kevin, but was killed soon afterward to end the Bloodaxe curse; the mace, seemingly powerless without Eric ended up in government custody.
Ever since his father's death Kevin has become a bitter teen with mounting difficulties stemming from the anger within himself, and no matter how hard he tries to remember the man who raised him he can only think of his father's alter-ego, Thunderstrike. Kevin cannot fathom why his father died saving a world that seemingly turned its back on him, and even the heroes he once idolized are nothing more to him than "spandex-covered glory hounds." After being expelled from various schools in California, Kevin’s family moved back to New York so Bobby could host a TV sports show, but Kevin's problems only continued. He was enrolled in the prestigious private school Maria Stark Academy, but he was caught fighting with another student for cyber-bullying, and his parents had to attend a meeting with his principal.
Soon after, Kevin was summoned by Steve Rogers and was brought to Rogers' mobile command center. Rogers wanted to give Kevin something that belonged to Kevin's dad, the Thunderstrike (mace), and Kevin eagerly accepted. Kevin was disappointed he did not transform into the hero his father was, but Rogers told him if he ever did trigger the change he could enroll at Avengers Academy to train with other young heroes. On his way home Kevin witnessed the Rhino attack a police transport, liberating captured Russian spies. In his wake Rhino overturned a car carrying a mother and baby, ruptured its gas tank, and toppled high-tension lines ensuring a stray spark would start a fire. As the mother was pulled to safety Kevin tried desperately to save the child, using his mace to pry the door open. Just as the car exploded his mace released its enchanted energies and Kevin became Thunderstrike and both he and the baby were saved. Rhino thought Thunderstrike was there to stop him so he immediately attacked. Although Kevin tried to fight back it wasn't long before Rhino got the best of him and escaped. As much as Kevin was surprised to have become Thunderstrike in the first place, his reflection shocked him that much more when he saw he was in his father's body.
In the Spotlight
By reactivating the mace, Kevin was noticed by the Asgardian trainee Valkyrior Gruenhilda and the sports mogul who believed he was a descendant of the gods, Adam Mann. Gruenhilda was sent by the goddesses Sif and Hecara to teach Kevin how to properly wield the mace's power while Mann sent his Spartans strike force to steal it. The Spartans forcibly took the mace despite the best efforts of Kevin and Gruenhilda, leaving the duo no choice but to invade Mann's home and take it back. Kevin transformed into Thunderstrike once more and fought the mystically armored Mann who nearly killed Kevin with an energy blast through his chest. Kevin transformed back to his human form, instantly healing him, but sent him running from Mann. The two rejoined their fight only to be interrupted by Mangog who was summoned to Earth by Mann's Mysticator. Gruenhilda saved Kevin from Mangog's rage even as the demon devoured Mann before their eyes, and then set his sights on Manhattan.
Kevin used a cell phone Rogers gave him to call in the Avengers to intercept Mangog, but Kevin finally realized why his father became a hero; someone needed to stand against the monsters. Kevin became Thunderstrike once more and stood side-by-side with the Avengers to oppose Mangog. Brushing off blow after crushing blow, Mangog seemed unbeatable until Kevin, Thor and Gruenhilda combined their enchanted weapons to banish Mangog elsewhere in the universe. Mangog would not go without a fight so Kevin forced him into the portal they created by striking him in the head with his mace. His forward motion sent him through the portal too, but Thor threw his hammer after him and brought Kevin back to the other side. Kevin was angered at Thor for never checking in on him once after Eric died, but Thor knew Hercules did and kept tabs on Kevin that way. Thor knelt at Kevin's feet for Eric’s sacrifice and Kevin's brave deed, beginning the healing process for their relationship. Kevin accepted his new role as Thunderstrike, and the first thing he asked Rogers to do for him was find the Rhino, so he could get his rematch.