Unfortunately I have to announce that this fanfic ends with the last chapter. For many different reasons I cannot endorse myself continuing this fanfic. One of the main reasons is because I have become an analyst of George's books and a theorist. The deeper understanding of George Martin's writing and the amount of work required to analyse his symbolism and narrative set up (as well as foreshadowing) just makes it impossible for me to combine the plot I had foreseen for this fanfic with his books, especially because I already am pretty certain that a lot of things will work out very very differently (such as the BwB, the Riverlands, the Vale, etc). And I'd rather read it in George's hand than my own.
If you are interested in analysis and predictions of what I think will happen in the Vale in tWoW, you can find my thoughts on my blog "Mythological Weave of Ice and Fire"
I am certain though that Gendry and Arya will meet again, that he is writing a romantic story involving them, but they are very young still.
OUTLINE I HAD PLANNED OF WHAT WAS TO HAPPEN
It's not the same, of course, and if I had it in me still to write it out, it might have had some changes along the way, since characters do what they do.
KL - Tyrion - Dany
Varys is never found again. Tyrion discovers the little birds in the walls, exposes Varys' secret to Dany who flees to Dragonstone in revulsion and wants the walls torn down of the red keep. Tyrin also finds a secret alcove/room in the red keep that contains a stash of a lot of stuff that Varys learned over the years: Kraken attacks, Others and wight sightings by the Night's Watch, Hardhome stories (all stuff that he should have informed the council about), how Varys was complicit in seeing Dany dead, how it was Ned Stark who requested Gendry to be sent with him to the wall in honor of the promise he made about Robert's children on Robert's death bed (aka Ned's letter mentioned in the dungeons was meant for Tobho Mott), how Varys knew well enough who were Robert's bastards and did nothing to save them except for Gendry per Ned's demand, and stuff about Robert's Rebellion. Varys was close but never realized that Jon was Lyanna's son by Rhaegar. Tyrion figures it out. He takes the information about the Others to Dany, who flies to the Isle of Faces to consult with the Green Men, like Rhaegar did. There she learns aSoIaF is her brother's son by Lyanna - Jon Snow.
The Riverlands take-over:
Arya, Jaime and the RL hostages there take Riverrun from the Freys without the Freys at the Twins realizing it. A deal is struck with Genna Lannister and her Frey husband who owned RR. Most of the "good Freys"(Roslin's brothers) already squire or live there. Most of them moved away from the Twins as a form of seeking refuge, since plenty of weird accidents have occurred at the Twins - even girls, are locking out their cousin on the balcony to freeze to death for example, all in the hope to be the inevitable heir. Walder Frey just finds it all funny. Some Freys fostered their children to families in the Vale. Basically Freys have started to murder each other. Edric Dayne takes Darry by stealth. When Arya is at RR, Gendry receives a raven about it at HH and the Vale army, Gendry's army and Arya's part of the army merge at RR. Edric Dayne remains at the other side of the Ford.
Sansa truly had LF killed for his crimes. She's somewhat envious of Arya-Gendry, while Arya feels insecure around her beautiful sister. Because Gendry and Arya have been apart for a while they struggle somewhat to reconnect and Arya wrongly suspects Sansa is the cause of it. By then Arya has discovered she is pregnant but withholds the information from Gendry. She misinterpretes a conversation/scene between Sansa and Gendry and sends him off by himself to take the Twins after a fight, while she intends to remain at RR.
Sansa confronts Arya and tries to make her see reason and to make up with Gendry, as he left her a note before leaving where he writes 'he loves Arya'. Arya remains suspicious of her sister, though she accepts nothing has actually happened. In her attempt to hurt Sansa, she reveals that Robb disinherited Sansa in his will. Sansa doesn't actually care for her claim of WF, but realizes that there's just too much water under the bridge for both sisters to be around each other and for Arya to trust her. Sansa takes the Vale army to Darry and thus intends to have the Vale army conquer the Twins from the KR side. Sandor re-emerges from Quiet Isle and connects with Sansa at that side of the Twins.
Arya eventually seeks to rejoin Gendry's army to tell him of the child she carries. So, they make-up, but he cannot risk Arya being anywhere near the fighting. With the help of Emmon Frey (Genna's husband), Walder Frey is betrayed and the armies can get inside the Twins to slaughter all. Emmon Frey is given Darry in reward for it, while the Frey heirs that sheltered in the Vale with the Hardyngs. Steffon Frey, son of Walton Frey, grandson of Stevron Frey (who died in the Battle of Oxcross and was Walder's eldest son) becomes new Lord of Twins. The Vance-Freys (children of Stevron's daughter married to a Vance) also survive because they joined house Vance in the rebellion agains the Twins. They are rewarded with one of the traitor houses. Edmure is restored as lord of RR.
Walder Frey is kept as prisoner, until Arya arrives. She beheads him the old way, wielding the sword herself. This is very disconcerting for her, since she's carrying a life and then already several moons pregnant. She truly starts to doubt whether she wants to kill the name that was given to her by HoBaW.
The North
Sansa and Arya part from each other at the Twins. She weds Sandor in secret and makes him the Guardian of the Bloody Gate at the Vale. She returns to the Vale with a part of her army, but surrender another potion to Arya and Gendry's command. The armies move for abandoned WF, but despite the armies Manderly refuses to give Rickon, claiming Arya must be an imposter since Arya's already at the Wall and she has no wolf to prove who she is (Nymeria is at the Kingswood). Jon is snowed in at the Wall and cannot come to confer she is who she claims to be and settle it all. But Davos helps Rickon to escape White Harbor. Gendry is out in the winter blizzards with an army searching for Rickon and Davos, while Arya gives birth to a daughter (which Gendry hoped to have - a daughter) in WF. Gendry returns with the frozen body of Rickon.
Bran never returns from the cave, but he guides Arya and Jon in dreams. The Wall falls and the NW is forced to retreat in the horrible weather, fleeing wights and Others. It all converges at WF, where Dany and Jaime join on the two dragons. Jaime and Viseria die in the battle against the Others, but not without Viseria having produced dragon eggs and Brienne carrying his child. The eggs are stored beneath WF near the hot spring. Edric Dayne saves Jon's life with Dawn and perishes. Davos dies too. Tyrion does the unthinkable - he forces Rhaegal to accept him as a dragonrider and joins in the battle, and finds his dead brother's body with the dragon. The battle is won, but at the great cost of many lives. The remaining dragons survive the battle itself but suffer injuries to which they succumb n the aftermath.
Jon and Dany meet and there are signs of them falling in love. But Dany believes she cannot have any children. The name that Arya was given was Mel's, and Mel knows it. She hopes to have Arya killed as a sacrifice to restore Dany's ability to have children. Arya knows she must kill Mel if she wants to live, but since the name was given by HoBaW it would force her to abandon her own child and husband. And as a mother, she just cannot find it in her to kill anymore. Instead, while Mel's fears and focus is all on Arya in WF godswood, Gendry kills Mel unexpectedly with Ice. Arya becomes Lady of WF, Gendry her consort, Jon and Dany are King and Queen of Westeros. Dany does not actually have any fertility issues. It just needed time.
The End