Since the formation of Krakoa, almost all of Marvel's mutants have played some role in the budding nation, even the ones who aren't X-Men. With some mutants serving as smugglers or black ops, the Quiet Council that dictates the laws for all mutants and rules over Krakoa. Although this group has been instrumental in developing mutant culture and their foreign policy, matters of defense are left to the combat-tested Great Captains who specialize in the art of war. One of these esteemed warriors is Illyana Rasputina, also known as the New Mutants' Magik. Although she might have mutant teleportation powers by birth, the Soulsword.
The importance of this weapon will almost certainly only grow with the upcoming X-Men event, X of Swords. As mutants arm themselves with their own blades, whether as a manifestation of their abilities or with weapons from their past, this battle will need those that can wield their swords to their utmost ability. As X has served as a Roman numeral in the past, in the case of Powers of X, it is likely that this event is specifically referring to ten swords that will be vital to the future of the X-Men. Given the Soulsword's power and its role in the history of Magik and the X-Men, it is likely that this sword will prove pivotal in this coming conflict.
Like Psylocke's own Psi-Blades, the Soulsword was originally a physical manifestation of Illyana's mutant abilities when it first appeared in 1983's Uncanny X-Men #171, by Chris Claremont and Walter Simonson. After being kidnapped by Belasco, the ruler of Marvel's hellish Limbo dimension -- which even has its own Ghost Rider -- Illyana spent much of childhood as both prisoner and apprentice to the demonic lord as she trained in both combat and magic. As her mutant ability to travel great distances emerged, Colossus' little sister finally decided she would fight for her freedom in a direct confrontation with Belasco. Needing a weapon, Illyana drew from her own lifeforce and used the resulting energy to forge a blade.
With this weapon, Illyana was able to disrupt magic, reverse certain spells and break through the most powerful of defenses. In addition, the sword empowered her own abilities in the occult, which gave her enough of an advantage to defeat and dethrone Belasco. As a result, the Soulsword became symbolic of the dominion of Limbo, and whoever possessed the sword also held the title as ruler of Limbo.
After returning to Earth and assuming the moniker of Magik, the now-teenage Illyana joined the New Mutants and served under Professor X. During this time, she learned of the sword's ability to armor its wielder in battle. While it usually reserved itself to her left arm, the armor could extend to the rest of her body in extreme moments of crisis. Magik continued to use the blade in battle and as a tool in her teleportation. Eventually, Magik lost her connection to the sword when she was de-aged and reverted to a child. With a new chance at a childhood, it would seem that the Soulsword would also be lost.
However, the sword was passed to Shadowcat, who was a close friend of Illyana. Although the Magik that had formed it no longer existed, the energy of the blade was able to survive the loss of its original creator as it found other wielders. As others used the sword, Illyana's weapon only grew more powerful with those that came into contact with it. Showcasing another ability, Kitty used the Soulsword to free Nightcrawler from demonic possession in an attempt to defend the sword.
Following Kitty, the Soulsword was linked to other sorcerers like Margali Szardos, who desired its power. After being given the blade by her daughter, Amanda Sefton -- who had convinced Kitty to give the sword to her -- Margali Szardos wielded the blade in a quest for power that led her to the Hellfire Club. Pushing herself too far, Margali was captured by Belasco, who used the weapon to regain his rule over Limbo with Illyana out of the picture. Finally, it's last major user was Sefton, who won the sword after Belasco's defeat and used it for good. Regardless of who used the sword, its time apart from Magik only increased its power with its contact to other magical beings.
As more demonic entities sought the sword, Jimaine sent the sword to Nightcrawler where it was attached to his very soul. After Nightcrawler was stabbed with a Souldagger, the Soulsword revealed itself; and it drew Illyana back to Earth in her demonic form as Darkchylde. With the Soulsword retrieved, Illyana finally was complete again, and her human form was restored. With the added powers from the sword's own travels, Magik rejoined the X-Men and served as the team's primary mode of teleportation and as a key battlefield asset.
While the sword was always seen as a slender blade, Illyana's time as a host to the Phoenix Force in Avengers vs. X-Men also had an impact with the Soulsword. Sharing a look with the Blade of the Phoenix, the sword was much larger and could now be used on physical beings as well as in mystical combat.
With the Soulsword at the height of its power, Magik seems ready to defend her nation from whatever threats may appear. In addition, her connection to Limbo could serve a pivotal role in expanding Krakoa's borders, as Apocalypse has already done. If Illyana's weapon cannot protect Krakoa, then a legion of demonic hordes will surely come in handy.