Xavin journeys to Earth to find Karolina. Karolina's parents had betrothed her to him, assuming that Xavin and his parents would perish while fighting the Majesdanians, their alien race. Xavin encounters Karolina shortly after her romantic advances are rejected by her friend Nico. Xavin, trying to convince Karolina to be his bride and return to unify their homeworlds, fights and pursues her runaway friends. Xavin finally tells Karolina that he won't force her to marry him, but he hopes that she will come with him to witness the animosity between their two races. He says that their marriage might end the war between the Skrulls and the Majesdanians. Karolina reveals that she is not attracted to men and doesn't want to live a lie, but Xavin alters his form to that of a human woman and persuades her to leave with the new female version of Xavin.
During the wedding ceremony, a fight breaks out between the two races, and Xavin and Karolina barely escape before the planet is destroyed. They return to Earth, where they help Karolina's friends rescue their friend Molly from the New Pride. Xavin impersonates Nico and takes a bullet for her, distracting Geoffrey Wilder long enough for Nico to untie Molly and escape. She also refers to herself a "runaway". Weeks later Xavin is more well adjusted, refraining from insulting Victor and becoming close to Molly (the only teammate other than Karolina to always refer to Xavin as female). However, Xavin is still more or less an outcast to the other members. Like the other Runaways, Xavin is an orphan (she told the group when she first appeared that her parents were dead because of the aliens' war).
Xavin joins the group but has trouble adjusting to her new surroundings and getting along with her new teammates, particularly Victor, whom she often offends with condescending remarks about robots. Although she is aggressive and headstrong, Xavin is motivated to protect her new home by her love for Karolina. Though she spends much of her "down time" in female form, Xavin usually reverts to the male Skrull form when in battle insisting that it adds to a more intimidating persona, despite Karolina thinking that it is sexist, yet still spends some time in male human form as well.
Xavin came to Earth to seek Karolina's hand in marriage, both to fullfill their parents arranged marriage and to try and bring peace between the Majesdanians and the Skrulls. Karolina initially rejected the proposal on the basis that she was a lesbian, stating that she didn't want to live a lie. When Xavin revealed he could change his gender at will, Karolina agreed to leave with her. However, their marriage fell through when fighting broke out once more, and the two returned to Earth and rejoined the Runaways. Their relationship is often rocky, due to Xavin's fluid gender and the fact that Karolina is still in love with Nico. Though Karolina has stated that she cares deeply for Xavin, Xavin has expressed doubts, believing she is not really the one Karolina wants to be with. Xavin, however, is very much in love with and devoted to Karolina, willing to do anything for her happiness.
Powers and AbilitiesEdit
Xavin, being a Skrull, has the species' natural ability to shape-shift. Xavin was also a member of a Super-Skrull-training program to create a new generation of Skrull warriors. As such, Xavin has the powers of the Fantastic Four: Mister Fantastic's ability to stretch and contort his body into any shape imaginable, Invisible Woman's power to render herself invisible and ability to create and project invisible powerful psionic forces to create any shape imaginable, Human Torch's pyrokinesis and flight and The Thing's superhuman strength and highly resistant, orange-colored, rock-like hide.
As stated by Xavin, he/she is still a Super Skrull in training, and can only use one of the Fantastic Four abilities at a time. Any more would invariably make Xavin lose control of his/her powers and be a harm to his/her surroundings. An example would be when Xavin was bombarded with high frequency sounds and lost control over his/her powers resulting in an explosion that destroyed a house. However, recently, he/she has shown the ability to control two of his/her powers at once in addition to his natural shape-shifting abilities.
Due to Xavin often changing through his/her three main form -- human female, true Skrull form, and human male -- both characters within the comic and fans question the nature of his/her gender.
As a Skrull, a race of shape-shifters, Xavin stated "For us, just changing our gender is no different than changing our hair color," implying that most Skrulls change their looks often. When asked by Molly about why she doesn't stay in one form all the time, Xavin replied that it was simply her nature to do so and doesn't see a problem in it, though it causes Xavin to start questioning her own nature.
Karolina is fixed on the idea that Xavin is female, and that Xavin isn't pretending to be a woman, just learning to be human. Although Karolina does truly love Xavin, even so much as to deny Xavin disguised as Nico, she does become depressed when a discussion of what Xavin's true form is comes to play between her and Nico.
In Civil War, Xavin is noted as being almost always in male form even when he/she would normally be female in the main book (i.e. the opening in issue 1 when the group went food shopping). Most fans seem to assume that it was a writer's or editor's choice to leave that part out. In Joss Whedon's six-part version, Xavin is shown going into his Skrull form as a female, so becoming male seems almost unnecessary. When the group is in the year 1907, Xavin takes a form of an older white male (both main human forms are black) most likely due to the times.
During an argument with Karolina, Xavin loses control and changes form into her female form, even more emphasizing for Karolina that Xavin is female, and when asked about it, Xavin replies that she didn't realize that the question of gender was in doubt.