Gunna Sijurvald was born of an Asgardian mother and a Magzi (a Troll tribe) father who had captured her. Even though she looks Asgardian, she was raised by the trolls. When the Asgardians captured her, along with a group of Magzi trolls, they named her Gunna after her mother and tried to introduce her to Asgardian culture with little success. She escaped with the Troll after Asgard was destroyed during the events of Siege.
When Luke Cage lead the Thunderbolts on their first mission to the Raft, they run into the young Gunna, who attacks and disables Ghost suit with her axe. Ghost tries calling for help, as the attacking girl wearing troll skin is about to slice him in two. Luckily for Ghost, Crossbones hits her in the side with one shot, causing her to fall down. Cage reprimands Crossbones for the seemingly lethal action, though the latter defends that he simply used a dart to penetrate the girl's ear.
Later at the Raft, Valkyrie identified the girl as Gunna, an Asgardian who was captured by the Magzi Trolls. She was locked in Asgard along with the rest of the Magzi in hopes of rehabilitating her before the trolls escaped after the eternal realm's fall. Valkyrie wants to take Gunna home but Warden Walker objects, stating that she and her troll brethren killed and apparently ate U.S. citizens and therefore, Gunna would stay at the Raft until a court trial could be enacted. Valkyrie retorted that if the Siege on Asgard never happened, then the trolls would never have been released. Luke Cage mediated the dispute, stating that they would leave the decision to Commander Steve Rogers. Valkyrie accepted the proposal and agreed to let Gunna remain in the Raft until then. As both Valkyrie and Walker departed, Cage advised Songbird to orientate Gunna for the duration of her stay and more importantly, teach her not to eat anybody.
During a prison riot, in which the power was knocked out, Songbird was attacked by a group of female prisoners. Troll, after bending the bars of her cage, ran out to save her while screaming in broken English. When Moonstone, who earlier just left Songbird, runs out and claimed to save the day, Songbird pointed out that she did nothing while Gunna saved the day.
While at lunch, the other female prisoners criticize her eating habits and describe her as an unbroken house pet. When they jokingly ask if she was a cannibal, she shocks the prisoners with a deadpan "Aye".
Thor visited Troll on the Raft and told the girl how she could be accepted back into the Asgardian lifestyle but Gunna attacked him, rejecting the offer and refusing to acknowledge her Asgardian status.
When a trio of male prisoners teases Gunna from behind the forcefield separating the men's courtyard from the women's. Gunna tries pouncing on them, only for the forcefield to block her way. Warden Walker and the prison guards show up to diffuse the situation and discipline the prisoners. Once it is settled, one of the guards confides in Walker that Gunna is too powerful for a juvenile facility but too young for the Raft.
A new Thunderbolt team is drafted in case the primary team dies on a mission, with Songbird selected as leader. Therefore, she and John Walker go around the Raft and select potential recruits.
Now on the Beta team of the Thunderbolts, Gunna was given back her original clothing, consisting of fur from an Asgardian animal and her weapon an ax that can cut through anything. On their first mission to Eastern Europe she shows loyalty to the team, saving Boomerang from being eaten by zombies.
Gunna was later selected by Luke Cage to be a part of the "beta team" of the Thunderbolts, alongside Boomerang, Shocker, Centurius and Mister Hyde. During the Serpent War, they joined forces with the "alpha" team on a mission aboard, before returning to find the Raft torn apart by Juggernaut after he became one of the Worthy. While dealing with the fallout from the Serpent War, several of the Thunderbolts took the opportunity to escape their handlers in Thunderbolts Tower, with Troll among them.
Travelling to the Past
Due to a failure of the teleportation technology of their tower (caused by Man-Thing), the tower began to move in time as well as in space. The Thunderbolts ended up in World War II teaming up with the Invaders to battle the Nazis. She promptly went hunting. After a brief skirmish with some Nazis, she starts to hang out with Mr. Hyde. Troll's war ax is also a pivotal tool for the Thunderbolts in the present trying to track her through time. They next end up in Victorian London and even further back in time, ending up in King Arthur's court in Camelot.
They eventually bounced back to the time of the original Zemo lead Thunderbolts team. After the Fixer killed his younger self this began to cause a collapse in reality which forced Fixer to assume his younger self's place. Troll and the Thunderbolts' next bounce sent them into the distant past, where they inadvertently saved a time-traveling Doctor Doom during the Pleistocene Era. He brought them back to the present but then turned on the group in Latveria.  Troll and the Thunderbolts time-jumped again, traveling to a far future, where Boss Cage patrolled Mondo City. They eventually reconnected with the remaining Thunderbolts in the present era and prevented the disaster that would have led to Boss Cage's future. Many of the Thunderbolts ran again, but they instructed Troll to stay behind because life on the run wasn't in her best interests as a young girl. 
When the Mother parasite attempted to overtake the world, only children and the young at heart were able to see her machinations for what they really were. Troll was among the younger heroes assembled by the Young Avengers to defend against Mother. 
Powers and Abilities
Gunna is a Troll/Asgardian Hybrid and possesses all of the various superhuman attributes common among the Asgardians, but-but fights with the savage ferocity of the Magzi Trolls.
Superhuman Strength: Like all Asgardians, Gunna is superhumanly strong and possesses greater physical strength than the average Asgardian female.
Superhuman Speed: Gunna is capable of running and moving at speeds much greater than that of even the finest human athlete.
Superhuman Stamina: Gunna's musculature produces considerably fewer fatigue toxins during physical activity than the musculature of a human being. She can exert herself at peak capacity for about 24 hours before fatigue begins to impair her.
Superhuman Durability: Gunna's body is much more resistant to physical harm than the body of a human being. She is capable of withstanding great impact forces, exposure to temperature and pressure extremes, powerful energy blasts, and high caliber bullets without sustaining injury.
Superhumanly Dense Tissue: Gunna's bodily tissues have about 3 times the density as the bodily tissue of a human. As a result, Gunna is actually much heavier than she appears. This increased tissue density also contributes somewhat to her physical strength.
Superhuman Longevity: Like all Asgardians, Gunna ages at a rate that is much slower than that of a human being. However, Asgardians aren't completely immune to aging, as some other god pantheons are.
Regenerative Healing Factor: Despite her body's resistance, Gunna can be injured like any other Asgardian. However, her metabolism enables her to rapidly regenerate damaged bodily tissue with greater speed and efficiency than a human being is capable of. Injuries such as slashes and punctures can fully heal within hours, whereas broken bones can heal within a few days. However, she isn't able to regenerate severed limbs or missing organs.
Exceptional Sense of Smell: Gunna has been shown several times using her sense of smell to identify creatures before they enter her line of sight, even up to several hundred yards (although it might go further). The extent and source of this ability has not been revealed (it might be part of her troll heritage).
Gunna is a formidable combatant and has received extensive training in unarmed combat and ax wielding.
Mystic Axe: Gunna uses an Asgardian ax which is capable of cutting through a tree in a single stroke, and can strike an intangible opponent.
- 41 appearance(s) of Gunna Sijurvald (Earth-616)
- 1 minor appearance(s) of Gunna Sijurvald (Earth-616)
- 24 image(s) of Gunna Sijurvald (Earth-616)
- 1 quotation(s) by or about Gunna Sijurvald (Earth-616)