This article is from the X-Men Comic Books FAQ, by Kate the Short (email@example.com) with numerous contributions by others.
The Soulsword was created from a piece of Illyana's own soul in issue #4
of the Magik Limited Series, and ever since then has been the symbol and
source of its owner's mastery of the other-dimensional realm of Limbo.
After the teenage Illyana reverted to her younger self in the wake of
the Inferno crossover, the Soulsword appeared in a rock outside
Excalibur's lighthouse for Kitty Pryde to claim. She, however, was quite
willing to leave it there, based on her previous experiences with it.
(She became the owner of the sword previously during the Secret Wars II
crossover, in New Mutants #35-37, when Illyana was temporarily killed by
In Excalibur #37, Dr. Doom showed up at Excalibur's door with a proposal
to go to Limbo with Kitty and the Soulsword in order to mine the place
for an energy-producing metal called promethium. Doom eventually tricked
Kitty into letting him have the sword, which he stuck into the heart of
Limbo to convert the entire planet/dimension/place into promethium. Doom
got out before the place went critical, leaving the sword behind. It was
claimed in issue #39 by the pseudo-demon Darkoth, who remained alone in
Limbo with the sword. And the matter was thought to be done with.
That is, until Scott Lobdell handed Warren Ellis a plot for the
Soulsword Trilogy (Excalibur #83-85). Lobdell was apparently completely
unaware of the aforementioned Promethium Exchange storyline, but we can
reconcile this by simply noting that something bad must have happened to
Darkoth between issues #39 and #83. In any event, the Soulsword started
to manifest itself in Kitty's possession again, and two other new
characters named Gravemoss and Shrill tried to take it from her.
Eventually the sword was passed off to Nightcrawler's sorceress
girlfriend Amanda Sefton, who made the mistake of giving it to her
mother, Margali Szardos.
Sometime after that, Belasco abducted Margali and stole the Soulsword.
In X-Men Unlimited #19, it was revealed that Margali had placed her
mind in Amanda's body, and placed Amanda in her body. She then took
Nightcrawler to Limbo, where she proceeded to defeat Belasco and knock
the sword away from him. Margali and Amanda were restored to their
proper bodies, and Amanda decided that she would became the mistress of
Limbo. At the end of that issue, the Soulsword, wielded by a silver-
armored hand, pushed through the dire. Readers never saw who that was,
so much energy was expended discussing whether Illyana was back.
Margali later turned up in a Claremont Fantastic Four annual that
dealt with the Hellfire Club. It's also in that FF annual that Amanda
likely made her first, uncredited appearance as Magik. In any case, in
the Black Sun and Magik mini-series, Amanda appeared in Illyana's
traditional silver armor, apparently holding the title and role of
Magik. The case seems closed.