I'll get us started:

-Ob Nixilus kills Gideon by drowning him in a puddle. Gideon Jura is dead; he died unceremoniously. Curiously, Jace was nowhere to be seen and neglected to aid his dying friend.

-Ob was severely injured in the fight with Gideon. He realizes he cannot contend with the Eldrazi swarming around Kozilek and the broken Sea Gate, so he retreats to heal. -With Kozilek's rise and Gideon's death, the allies are in complete disarray. They are being routed. The notable ally leaders (Munda, Noyan Dar) attempt to organize a retreat. Noyan finds and saves Kiora; Munda finds and saves Nissa.

-Some generic filler about rallying the allies. General Tazri's appearance on the battlefield and her assuming ultimate command following Gideon's death. Show how battling against Kozi's brood differs from battling against Ula's. Perhaps a note on how the two broods work cooperatively to be more effective than either is alone. A glimpse of hope. Jace, Nissa, and Chandra take their oaths.

-A UR on Jace. It talks about how Kozilek's rise affected his powers, and he was helpless as Ob murdered Gideon. He should show symptoms of affliction from Kozilek's presence, including a theme of panic and despair that runs through the UR. After watching Gideon die, Jace goes to find Ugin. Ugin informs him, among other things, that all is most likely lost, and that Kozilek's distorting effects on Zendikar affect Jace more than others since he is a telepath (the authors can pick their own devices for the reason). Ugin says that the two need to find Sorin. Jace strengthens his resolve now that he is farther from Ulamog, says that he believes they can still defeat the titans through cunning and cooperation. Ugin says that defeating the titans was never a possibility, but he concedes that they may yet still contain them. He reiterates that they need to consult Sorin. Jace and Ugin make plans to find him, but Jace first wants to inform the other walkers (Nissa and Chandra) of his pending absence. The UR ends with him taking his oath.

-Jace and Ugin planeswalk to Innistrad and meet with Sorin. Creative can use this meeting to foreshadow some events in SOI. Sorin says that without Nahiri, he doubts they can neutralize the Eldrazi within Zendikar again. Ugin proposes that they quarantine the entire plane of Zendikar (authors can determine whatever the reason); its inhabitants will be trapped with the Eldrazi, but, Ugin hopes, the titans won't be able to escape once they finish devouring Zendikar. Of course, planeswalkers would no longer be able to travel to or from Zendikar once the quarantine is in place.

-Back on Zendikar, things are going poorly (as they should). With two titans and their brood's ravaging the landscape, Zendikar and her inhabitants hardly stand a chance. Nissa and Chandra are doing all they can, but the war is slowly being lost. Jace reappears and shows the same weakness that he showed in the aftermath of Gideon's death. He sees how badly Zendikar is losing, and his resolve is shaken. With no hope left, he confronts Nissa and Chandra with the old-walkers' plan to quarantine Zendikar. The women are outraged, and fight harder than before to prove their predecessors wrong.

-Some UR on Kiora: how she copes with getting Lorthos killed, how she proposes to fight the Eldrazi, and some more insidious effects of Kozilek's presence on the merfolk.

-Zendikar is almost certainly lost. By chance, Jace and Kiora meet on the battlefield. Kiora is still scarred from he first encounter with Kozi and has had little hope. Jace is afflicted with induced despair; he can tell she is hopeless and frightened as well. He informs her that Ugin and Sorin intend to quarantine the plane if the war does not turn soon. Add some weird romantic element if you want, I don't really care.

-The preparations are complete, and Ugin, in a great burst of strength that will leave him nearly powerless for many years, is ready to quarantine Zendikar. Jace, Chandra, and Nissa must decide to stay or to leave. Jace tells the other two that he cannot stay; he doesn't think Zendikar has a chance. Nissa refuses to leave her home to ruination. Chandra must tell Nissa that she cannot live trapped with death- she cannot stay on an isolated, dying plane. She asks Nissa to come, but Nissa is adamant to stay. Nissa berates the other two, the shames them in an effort to get them to stay. It doesn't work. Finally, she implores them; Chandra looks at her tearfully, but cannot stay. Jace cannot even look at her. The two planeswalk away, and Zendikar is quarantined, without reinforcement against the two titans.

-Nissa and the allies fight bravely against the eldrazi, but they're overmatched. Nissa scours the plane for any way to defeat the eldrazi. During her search, she comes across a weakened Ob Nixilus fighting against some powerful eldrazi (maybe a pair of desolation twins? Maybe the Bane of Bala Ged? Whatever, as long as it's some eldrazi behemoth). Although he thrived on the pain and suffering of others, as Zendikar died, there was not enough people remaining to replenish him as he fought off the ever more, ever larger, ever stronger eldrazi. His wing is still battered from the original confrontation with Gideon. Nissa slays the eldrazi harassing him, then turns to confront him. He knows he is too weak to fight her (even though Nissa herself is getting weaker as the plane itself dies), so he tries to planeswalk away. It fails- the quarantine has been placed successfully! Nissa informs him of the plane's fate. Ob, realizing he is trapped, attempts to barter. If she will spare him, he will help he fight the Eldrazi. He thrives on death, but doesn't want to die here himself. He realizes that Kozilek cannot be controlled. Nissa, not to be fooled twice, refuses the demon's offer and kills him in the final, moral victory of the set. There is little hope for more victory.

In summary Gideon: Dead Nissa: Assumed Dead Chandra: Escaped Ugin: Escaped Jace: Escaped, but altered. I would have him be a black-blue walker in his next rendition. Ob Nixilus: Dead Kiora: Fate unknown

This storyline is more "realistic," in my opinion (at least, as far as fantasy could be), in that the eldrazi titans are not defeated, but at least contained (with the exception of Emrakul). It allows creative to develop some actual character for their characters; Jace is knocked down a peg and shown as cowardly and weak. Nissa gets to die a hero's death. Kiora gets to be not only a bitch, but a fickle bitch who leaves her people (or she can also die a hero, whichever creative wants). Furthermore, it allows a bit of hype to build up around SOI while weaving the two stories together ever so loosely.