Not that I ever believed Illyana was affected by the T/O virus, much less 'loss of powers' by some petty US military group; see Project Purgatory vs The White Devil back under Zeb Wells. I saw it as plausible deniability for her to kick ass and take names.
Illyana basically always nerfs herself, for subtle, twisted, yet ultimately understandable reasons, namely that she wants to live a life, and have friends & family, rather than becoming a world-conquorer (see her discussion with the demons that tried to spring her from detention in her bomb jacket days.)
We've seen her do power feats beyond the Silver Surfer, and later no one even remembers them... We saw her manipulate Stevie Hunter's memories way, way back in TNM v1 #14, and I wonder how "Xavier/Emmaish" she is, manipulating people's perceptions of what she can do, underestimating her constantly.
Frankly, between Scrying, Stepping Disks, and Dominion over Limbo, there's very little she can't do... Except for not corrupting and poisoning everything she touches, her primary dilemma since her origin, which she finally addressed by apprenticing under Strange.
[Her killer application: given the maximum Limbo/Earth time differential we've seen (7 years in 7 seconds or so in her origin), she could sit in Limbo, scry on an Earth frozen in time, and teleport anyone and everything to anywhere and anywhen she wants (and perhaps just their heads) not even using the reality manipulation she can do in Limbo (Note also anything Belasco could do, she can do better: see her return in New X-Men for how badass he was, then notice what she's done to the Elder Gods, Dormammu, Juggernaut a couple times, Dr. Strange, the Inhumans, that one space god, the Demon Bear, the World Eater, Enchantress etc etc... Plus when the Beyonder Himself tried to obliterate her, the SoulSword, Soul Armour, and Beatrice Medallion passed to Kitty, ignoring the Beyonder's best efforts to obliterate the New Mutants without a trace.]
I think it's worth noting that the "boob window" is seemingly gone in the costume as well. Could be that they are taming down the Bachalo costume to look more in line with the others, but also makes me wonder why they wouldn't pull the others OUT of the training uniform as well than. Dani's never looked out of place kicking ass in jeans and her fringe jackets for example.
Or honestly, it's quite possible everyone will have different looks on the inside of the book and the cover just helps the viewer recognize everyone right away on the first cover to help generate sales.
I know I have stated it repeatedly, but I love Bachalo's Magik. The "pointy head-dress", the "boob-window", the "FF Soul Sword"...Can't get enough. So I am glad she is moving back to a similar version.
I really hope the rest of the team develops unique looks as well. I love the new design for Cypher!
We know with utter certainty that she's been Machiavellian about it in the past, perhaps better than Fisk himself, given that she can 'Replay' any scenario she wants until she wins, namely the Project Purgatory/Elder God/Legion War, plus lots of suspicious victories (Pwning Cyttorak & Juggernaut from a jailcell etc.)
There is certainly the question of whether she has not just psychic shields, but also brainwashes others, especially to forget her, her powers, and potential power level.
Just by reading what we see on the page literally, we know that several Avengers and other powered folks meet her and then seem unfamiliar with her the next time they meet (Captain America met her three or four times before he started recognizing her... Perhaps that's why she wore the training costume for years, then branded herself with the boob-window & headspikes later.)
A literal read can easily suggest that her 'variable strength psychic shields' and dozens of other nerfings require that none of the other X-Men remember that she has psychic shields, can decapitate armies, can summon millions of demons & kill gods by the hundreds, can teleport buildings to Limbo and starships across galaxies and the centuries... only we the audience remember those things.
Nobody writes Magik as an anti-hero. Not since Gillen.
Sardonic? Dark? Sure.
But she's 100% a Hero.
And thats what seperates the heroes from the antiheroes. Murder is not a heroic trait and anyone that can casually do it falls in anti-hero territory. Theres no remorse or conscience when she kills. What she did in UXM wasnt like some isolated case but something she would totally do under most circumstances. Heck she was having demons in Limbo eat Inhumans in IvX. She isnt 100% a hero as she does some horrible things that most heroes wouldnt dare do. Theres nothing wrong with her being labaled an anti-hero as thats what seperates her from the other NM and makes her interesting.
The Punisher deep down is a villain, not an anti-hero.