(I haven't been reading Legion of X so if there are any references or connections I've missed, please feel free to add them!)
We open with the preview pages, Vox Ignis/Banshee inside the Sanctum Sanctorum in New Essex (formerly New York). They were sent by Mother Righteous to scavenge for items of power but diamond Sinister's assassins are closing in on them. Banshee is concerned with their arrival, Vox tells him to calm down, Banshee is like we need to leave because all of the occult "eejits" fled to Otherworld and there's nothing left here to find. Vox says Mother does not reward failure so they must approach the problem from a different angle.
The Legion of the Night appear and attack, 6 assassin chimeras of Nightcrawler and the likes of Wolverine, Sabretooth, Domino, etc. Banshee tells Vox to use their Scream o' Change on the assassins but Vox says they've tried it on countless Sinisterized people but it doesn't work. Banshee says they don't have a choice so they try it on the commander Wagnerine first. She pauses. NightEmplate comments that her thoughts have suddenly become alarmingly "unsinister." She suddenly stabs Nightplate in the head and tells Voxshee to free as many of her kin as they can. It worked! NightDomino, real name Auntie Fortune, is freed next. Nightbretooth tells the others to scatter so they can escape and inform the council. Auntie is like nah and fires her gun, bamf'ing bullets around the room that kill Nightbretooth, NightPyro, and NightToad. She calls them "lucky leaps". NightSpidey, real name Wallcrawler, was freed during the process as well. Vox suggests the three of them flee before more assassins show up but Wagnerine wants to stay with him. Free of the evil influence, Wagnerive says they were born in wombs of steel, passengers to the ambitions of a disgusting mind. She says they need to know what they exist for, what is their higher purpose.
Title page: We're reminded that Nightcrawler was undergoing excess mutation just before the Sinister takeover of the world. Sinister was unable to exploit his genes for a long time until one day he suddenly was able to. Kurt unfortunately had been consumed by monstrosity over that time.
Data page: Sinister describing how it took 9 years, 2 months, and 6 days before he could finally utilize Kurt's genes. He doesn't know how it happened but he's finally able to make "BAMFSNIKT" a thing, finally able to make teleporting assassins. At the bottom of the page is a note to himself: "Did I ever actually get around to killing the original Nightcrawler?"
Vox is with Mother Righteous at the House of the Fall, formerly the Summer House on the moon. He's about to update her on his mission but she says they have a meeting to attend. She uses her golden globes to teleport them to a bar where she approaches Orbis and Stasis having a drink. They do not know her but she knows them. She introduces herself and says they haven't heard of her because she didn't want them to. She explains that 10 years ago a bunch of the X-Genes (mutants) were bewitched and Sinister was unable to use them (see Legion of X). It took her years to fix the spell using counter spells, sacrifices (we see her sacrificing Margali), deals, etc. Stasis calls her a fool, revealing that Orchis commissioned that hex to prevent Sinister from exploiting some of the most dangerous bloodlines. He says it's her fault he now has his dangerous assassins. He tries scanning Mother with a device to see if she's also a clone but she is not. He demands to know why she's working for Sinister.
She orders Vox to kill Stasis. His white tiger bodyguard, Bornan, leaps to protect him. There's some words about magic which Stasis scoffs at, then Wagnerine, Wallcrawler, and Auntie appear, killing Bornan. Stasis deploys his own personal defenses - teleportation baffler, improbability dampener - to neutralize their powers. He grows tentacles which grab Wagnerine by all four limbs but her tail comes around and revealing its own claw, stabs Stasis in the forehead.
Orbis applauds, saying he was afraid he was going to have to listen to Stasis' alliance proposal. Orbis hired Mother to kill Stasis! He says it was ingenious of Mother to cure the mutant monstrosity hex which allowed her to turn Sinister's assassins. Mother reminds him that her price for the task was answers. She asks Orbis what he's planning that has Sinister knickers in a twist. "What's the big idea, brother dear?"
Data page:
So that's why Orbis is at the World Farm in SatB #1. They're back at the House of the Fall and we learn that it was Orbis' idea to steal the Moira clones because he didn't want this reality to be reset. Why? Because, as he tells Mother, he has "the processing power of the World Farm. Crunching possibilities to find a path to the highest throne." As long as he has the Moira clones it doesn't matter how long it takes. He tells Mother to stay out of his way and he'll grant her safe passage through his dominion. He thanks her for her help and teleports away.
Mother says they need new recruits, new believers, and sends Vox and Wagnerine's crew out. They recruit Sinister Colossus from the Savage Land but only him so far as the Scream O' Change isn't working on most people. They arrive at Sinister's prime cloning facility, where the chimeras are from, and encounter big head Nemesis and Nightcrawler. Poor Kurt is still suffering from the effects of the original Margali spell, growing more monstrous and mindless. Vox says only resurrection could restore him to his prime but only Sinister has the means. They free a young NightPixie and a brain in a lantern which is Cortez, which was being used to amp up the assassins. Vox notes that the Nightkin are happier free than servile. They are kind. They are Kurt. Kurt as he was, in the Spark of their souls.
They return to Mother with their findings as they explored various places trying to recruit. Mother shows them an image of the Moira clones surrounded by that black globe we saw in SatB #1. She calls it unholy and says she can only see it via remote viewing but that it falls to them to cleanse it. She also shows them an image of a weapon, The Reliquary Perilous, which they must build. It will purge the Sinister Strain from the heart of every mutant. If they want to build it they'll need someone on the inside and asked for volunteers. Wallcrawler says he'll do it because he can feel Sinister, the diamond devil's, influence returning with an itch at the back of his head. He wants to honor Kurt by doing this and Mother agrees, using Cortez to amp him up. The sweet young man teleports to the Moira clone globe but is killed by a forcefield. They mourn his death and chant his name. Mother says they'll figure out a way to get inside and in the meantime, they'll build the weapon. The Crawlers are dedicated to her and Wagnerine asks what they need to steal.
"Heh! What else, love?...