Illyria vs Magik

In years past a match up like this would not have been necessarily possible, but thanks to the new trend of continuing TV shows in comic book form, we can do anything now!

VS

Illyana Rasputin "Magik"

For the sake of this mash-up I am going to use each of their best forms.  For Illyria, I am using the version of her just after she took over Fred's body but before she went nuclear with power.  For Magik, I am using her current form since its the one with the most mastery and control of her powers.

Illyria

Powers/Advantages

1) Strength - In this form, Illyria is supremely strong.  She \is shown to be strong enough to take on two vampires at once or fight a fire breathing dragon alone and unarmed.
2) Invulnerable - She is also incredibly durable.  While at full power she is able to withstand swords, axes, and dragon breath as well as take blows (if they land) with offense rather then injury.  Her skin, which in most areas is more like armor, is also capable of regeneration and healing itself.
3) Time Distortion - While it may appear that she vanishes from sight and reappears elsewhere, she actually is able to manipulate time in a controlled area.  She has been shown to slow down time for other while she moves past normally but one can guess that she could also speed up time for an intended target.
4) Speed - Having nothing to do with her time abilities, Illyria is also a very quick and agile opponent.  While not fast enough to move as a blur, enemies (and Spike) have been hard pressed to land even a single blow on her.
5) Empathy - She is able to sense the emotions of those around her. 
6) Fighting Skills - According to Spike, who sparred with her to gauge her abilities, she fighting style is a mixture between Tae Kwon Do and Brazilian Ninjitsu

Weaknesses

Illyria doesn't have any real weaknesses in this form.  She is very prone to disorientation due to the stark newness of her surroundings, and it is also possible that her empathic abilities are slightyl overwhelmed by all the raw human emotion around her.  She also has trouble dealing with the emotional remains of Fred within her.

Magik

Power/Advantages

1) Teleportation - Her primary mutant power is her ability to conjure "stepping discs" into the demonic realm of Limbo and then from there she can summon another disc to anywhere in space or time she chooses.
2) Soul Sword - This blade is fashioned from a piece of Illyana's own soul.  It can not hurt normal people or objects but will disrupt or cancel out magical beings, constructs, or spells. 
3) Soul Armor - Whenever she summons her Soul Sword she is also covered by an enchanted armor made of the same material as the sword.  This armor is shown to be able to resist mighty blows and also grants her a measure of super human strength.
4) Magical Prowess - During her time in Limbo Illyana was an apprentice to both Belasco and Storm.  From Storm, she learned all about white magic and its healing effects, but by Belasco she was tutored in the Black Arts.  She uses a combination of these teachings to create many magical effects including: 

• Summoning lesser demons
• Blasts of magical energy
• Necromancy
• Astral Projection
• Possession
• Scrying (using her enchanted mirror)
• Generation and manipulation of eldritch fire
• Magical Force Fields
• Casting magical spells from arcane lore

5) Fight Skills - During the years in Limbo, there was a period where she was taught how to survive on the harsh Limbo terrain by Cat, an alternate version of Kitty Pryde twisted by Belasco's magic.

Weaknesses

Illyana's main weakness is that the majority of her magical abilities are restricted to only when she is in Limbo..  Outside of Limbo she is limited to just the use of her stepping discs and her Soul Sword.  Also, her Soul Armor must by summoned like her Sword so, if caught unaware without it on, she can be injured the same as any normal human.

Fight!

Let's just assume that this battle start in our dimension, the first thing that Illyana would do is try to get Illyria into Limbo so she can access the full array of her sorceress powers.  In years past this would never happen but now that she has fully mastered her stepping disc power there is a much better chance of success.  Now with Illyria's time distortion abilities this is still much easier said then done but between dodging stepping discs and swings from the Soul Sword (which I believe would cause incredible damage to Illyria who is chock full of magical energy) I think that eventually Illyria would misstep and find herself within the demonic realm of Limbo.  As long as they remain on Earth this batlte would pretty much be a game of cat and mouse between the two "women" and if god forbid Illyria caught Magik, she would brutalize her (although the second Illyria took her hands off of her, Illyana would teleport away).

Once the battle made its way to Limbo though the odds change considerably.  First, Illyana would summon the strongest demons under her command to restrain the she-god, which Illyria would promptly tear to shred.  This would give Illyana the moment reprieve she needed to build some of her own mystical energy and unleash an arcane blast of fury at Illyria that would her down for a few moments.  These precious moments would give Illyana the needed seconds to stab her with the Soul Sword.  Short of decapitation, it is doubtful that this would kill Illyria still and coupled with her rapid healing skin she'd be back up on her feet soon enough.  

This battle will predominantly be determined by not just Illyana's ability to stay out of Illyria's reach but also her ability to get Illyria to Limbo.  As long as she is on Earth, she can avoid and dodge Illyria all she wants but she can't do any real damage except, again, to cut Illyria's head off with her Sword which I doubt Illyria's time powers will allow while still on Earth.  In Limbo, Illyana's power greatly increases and she gains the ability to properly damage Illyria with her magic but even still she has to contend with Illyria's constant regeneration.

In the end, I think that Illyria would win in this battle just based on shear endurance.  Even with all of the arcane might at her disposal, eventually Illyana's magical resources would be tapped out and Illyria's "armor" would continue to repair itself throughout the battle.  There is also the chance that Illyana could get killing head shot on Illyria but I really think that would be a slim chance.