Storm Knights can proceed to Scene One, or they can play Scene Two, which assumes the Knights are needed to fight the more-powerful forces. They are not required to do both.
Most of this scene should be a character-interaction scene, as they make preparations to cross the Storm front and assault the blessing ceremony. The obstacles to success are listed below:
During the showdown, Mobius' face will finally be revealed: the Curse of Amat-Ra is that the father renounced his son, and Mobuis has no face. Mobius must persuade Amat-Ra to lift the curse, which depends greatly on what position Amat-Ra is in. Amat-Ra has come to, in turn, give his son a chance to repent his evil ways and renew his faith as his father has. While Mobius is under the influence of the Darkness Device, there is no way this will happen.
"It is complete!" declares Mobius. "Now I have the ultimate power in the cosmverse! Look on as I crush your world with but a single thought!"
From behind him, the Gaunt Man appears, uttering: "Indeed." Then he invokes the reality storm.
The Gaunt Man had the talisman secretly planted on the girl, corrupting her as she made the decisions of who lived and died. The Gaunt Man had her subtly alter the plan of possibilities so that he could become Torg. Unfortunately for him, he could not make his success definite without alerting Dr. Mobius, so the outcome is not final yet.
The Gaunt Man has secretly merged with one of his stelae, giving him a Reality skill on a par with Mobius and the Kefertiri Idol. Mobius is also mostly drained of possibility energy in the ritual to become Torg. As the reality storm grows, the destruction is so intense that the Nameless One's attention is gained. [I did the math; when the storm reaches a radius of 5 km the energy will be equivalent to stopping the earth. It will also breach the Earth's crust at that point; such destruction should be more than enough to attract the Nameless One]. Within minutes, Earth will be destroyed.
Malraux may appear and tell them that the Nameless One will destroy the Everlaws, ending the reality storm between Mobius and the Gaunt Man. He will then leave with Mara to return to Kadandra, to learn of man in harmony with machine and to begin atonement for his innummerable sins. Malraux was corrupted of his own free will, and is just now learning of redemption.
Djil says they can also do nothing, and wait to see if the storm passes before the Nameless One arrives.
Heketon may appear and offer itself to one of the Storm Knights. It declares that it is the Gaunt Man's method of True Death; without it, the Gaunt Man cannot survive. A side note: if a Storm Knight attacks Heketon with the Power of Apeiros it will be destroyed-and the destruction will automatically attract the Nameless One.
If the Storm Knights suggest that losing the power of Apeiros means that the world will be destroyed, Djil will say "Apeiros will always be here as long as we are living".
If a Storm Knight sacrifices himself/herself, the reality storm ends as the Everlaw of Two is destroyed. Enraged and within such proximity to the Cosmverse, the Nameless One recalls all its Darkness Devices, and Mobius and the Gaunt Man die horribly as the objects are physically ripped from their bodies. With no more power of Eternal Corruption, the Gaunt Man is sent to his final judgement.
Soon, the Everlaw of One does reassert itself from the belief of the people. The Pure reality of Core Earth spreads across the world, and the people are not destroyed when they transform because the Everlaw of One no longer requires it. The history of the Near Now begins to alter itself to comform to the existing reality, and the Possibility Wars become no more than a tale to be told throughout the cosmverse.
What happens next would be largely up to the character that made the sacrifice. Many possibilites are laid out before him or her, possibly as portals to walk through. Rather than the player making a decision now, it's left to the sequel. The Possibility Wars are over.