The Strucker Twins' DNA was altered by their father Baron Wolfgang von Strucker while they were still embryos. The twins are white supremacists and strive for the resurrection of the Fourth Reich.
The Strucker twins despise Magneto for his role in their father's supposed death some years after World War II. They later attack Magneto during his trial in Paris by the International Court of Justice for his crimes against humanity. The X-Men eventually stop the duo from attacking Magneto, but they manage to escape into the sewers.
The Strucker twins have encountered Storm of the X-Men, in which Storm stops Andrea's assault on a native woman in Africa. Andrea gets revenge for Storm's victory by shooting her in the head and then leaving her to die.
Fenris later resurface as part of the team called the Upstarts, a group of mutant millionaires controlled by Gamesmaster and Selene Gallio, the Hellfire Club's former Black Queen. They engage in a campaign of mass murder as part of a game organized by the mutant telepaths. The twins try to recruit Omega Red for the Upstarts but fail to do so. Fenris finally met their match when they tried to kill the former New Mutants member, Wolfsbane. Wolfsbane with her new X-Factor teammates easily defeats the pair.
After their defeat Fenris join a group crime lords who intended to divide up the empire left by the defeated Kingpin. The Crime Lords consisted of Slug, Hammerhead, Tombstone and their own sibling Werner von Strucker.
The twins didn't believe that Werner was their brother, and this conflict caused the meeting to degenerate into a fire fight. The twins tried to kill Hammerhead but he was eventually rescued. Werner is killed by their own father who was disguised as one of his assistants. Baron Wolfgang Von Strucker later recruits the pair into his organization. The team fights the new Citizen V, until Andrea discovers that he is actually Baron Zemo.
Baron Helmut Zemo is then decapitated by Nomad under orders of Henry Peter Gyrich. Techno then transfers his mind into the comatose body of the second Citizen V, (John Watkins III). Andrea is killed by Zemo to keep his secret. Andreas, distraught after his sisters death, takes the identity of the new Swordsman and joins the New Thunderbolts. Disturbingly, by tanning his sister's skin and attaching it to his sword, he is able to keep the powers he shared with her as a part of Fenris. Andrea later returns but is revealed to be a clone created by Arnim Zola, who Andreas had contracted him to do so. Director Norman Osborn is concerned at the speed at which she had been cloned.
Fenris and the Thunderbolts go into battle against the Skrulls during the Secret Invasion and they witness Moonstone after she takes out Andreas and attempts to make a deal with the Skrulls. Andrea then attacks Moonstone but while distracted, Bullseye kills her from behind. Andreas later confronts Osborn because he was not offered a place in the roster of the new Dark Avengers. Andrea also found out that Norman had never planned to fulfill his vow to resurrect Andreas or provide them with a full presidential pardon after his time with the Thunderbolts ends. Norman then kills Andreas with his own swords and dumps him out a near by window.
Andreas von Strucker
Andreas von Strucker and his twin sister Andrea were the children of Nazi supremacist Baron Strucker, who saw great potential in their future. While still in-utero, the children were bio-engineered to have superpowers, with each gaining the ability to fly and fire beams of concentrated plasma as long as they were in physical contact, usually accomplished by holding hands.
Now known as the Fenris Twins, the two came into conflict with the X-Men and their enemy Magneto numerous times, believing the latter to have been responsible for the death of their father. They would later join of group of mutant millionaire supervillains known as the Upstarts, led by the telepathic Gamesmaster, until they were defeated by X-Factor.
Resurfacing several years later, the two took on the Thunderbolts, secretly led by the villainous Baron Zemo disguised as "Citizen V". Zemo would kill Andrea, leaving Andreas both powerless and distraught. Seeing potential in his abilities and the opportunity to exploit his fractured mental state, Zemo employed Zebediah Killgrave, the Purple Man, to train him as the new Swordsman.
While receiving his training from Killgrave, Andreas was given a leather strap made from his sister's skin which he used as the grip on his sword to harness his powers. Wanting to strike back at Zemo, he infiltrated his team of Thunderbolts under his new identity, even appearing to aid the team by Songbird from Killgrave's sick games. However, he showed his true alliances at last, stabbing both Atlas and Mach IV.
When the Purple Man was eventually defeated by the Thunderbolts, Andreas was confronted by Zemo, who revealed himself as the mastermind behind his training. Despite this revelation, Andreas stayed with the group. He would continue his activities with the team even after their transformation into a government-sanctioned organization during the Initiative.
Secret Invasion and Osborn
When Norman Osborn was made leader of the new Thunderbolts, he attempted to give the team a new image in the public eye as a legitimate hero organization despite having an all-villain lineup. While active on this squad, Andreas was seemingly re-united with his deceased sister Andrea, who claimed to have been resurrected by Arnim Zola's cloning process. The two began a physical relationship while Osborn became suspicious of how quickly Zola was able to create her. When it was later revealed that Andrea was in fact a Skrull shapeshifter attempting to infiltrate the team as part of its people's invasion, she was killed by Bullseye.
When the Skrulls launched a full-scale attack against Earth, the Thunderbolts were among the combatants present during the final push in Central Park, with Norman Osborn landing the killing blow against their queen, Veranke. After he is promoted as the new director of S.H.I.E.L.D., Osborn announces that he will dismantle the current Thunderbolts program. While overseeing the shutdown of Thunderbolts Mountain, an irate Swordsman confronted Norman, who seized his sword and murdered him in a psychotic tantrum.
Andrea von Strucker
Like their father, the twins are white supremacists, have great sympathy for the Nazi agenda, and strive for the Fourth Reich. The Strucker twins have made numerous appearances in Uncanny X-Men. One of their earliest appearances happens in Uncanny X-Men #194, in which Storm interrupts Andreas' attempted assault on a native woman in Africa. Andrea retaliates for Storm's humiliation of her brother by shooting her in the head and leaving her to die.
The Strucker twins despise Magneto for his role in their father's seeming death some years after World War II. In Uncanny X-Men #200, they conduct acts of terrorism and finally attack Magneto during his trial in Paris by the International Court of Justice for his crimes against humanity. The X-Men foil their assassination attempt, but Fenris manages to escape by allowing themselves to be swept into the old city sewers.
The twins later resurface as part of the Upstarts, a group of mutant millionaires who engage in a campaign of murder as part of a game organized by the mutant telepath Gamesmaster and the Hellfire Club's former Black Queen Selene. The twins tried to acquire Omega Red for the Upstarts but failed. The twins ultimately met their match, though, when they tried to kill Wolfsbane, the former New Mutant. Along with her new X-Factor teammates, Wolfsbane easily beat the twins.
The twins joined a conference of powerful criminal leaders who intended to divide up the empire left by the fallen Kingpin. Among the members of the conference were Slug, Hammerhead, Tombstone and their sibling Werner von Strucker. The twins did not believe Werner was actually their sibling. This, and other arguments, caused the conference to degenerate into a shouting, shooting and blasting match. Fenris attempted to kill Hammerhead but he was rescued. Their sibling is soon after killed by their father, who had attended the conference disguised as the assistant to Werner.
The twins resurfaced in the pages of the 1999 Citizen V mini-series, where they were seen working with their father Baron Wolfgang Von Strucker. During the mini-series they fight Citizen V, though Andrea discovers that he is actually Baron Helmut Zemo. Having been decapitated by Nomad under orders of Henry Peter Gyrich, Zemo had survived when Techno, to Zemo's own surprise, transferred Zemo's mind into the comatose body of the second Citizen V, John Watkins III. Zemo quickly kills Andrea to keep her from telling anyone his secret.
After Andrea's death, her brother became the fourth Swordsman and joined the New Thunderbolts. By tanning his sister's skin and using it as the grip on his sword, he is able to maintain the powers he shared with her as a part of Fenris.
Andrea mysteriously returned, not long after Andreas had contracted to have her cloned by Arnim Zola. However, the speed at which she had been cloned concerns Thunderbolts' director Norman Osborn. Andrea accompanies Andreas and the Thunderbolts into battle against the Skrulls during the Secret Invasion, and witnesses as Moonstone incapacitates Andreas and attempts to make a deal with the Skrulls. Andrea then attacks Moonstone, and while she is preoccupied with Moonstone, Bullseye kills her from behind.
Andrea and Andreas returned to the living and have opened Club Fenris, a supervillain club in Manhattan. When questioned about their demise and subsequent return from the dead, they stated that their father "took care of it".