Well, the good thing about MK storyline is that you can expeculate a lot of future events until the next game will be released. Here goes some of my Ideas. Sorry about my english if there is some errors ok? Here goes.

The main plot - Onaga wins the battle again. He merge the Kamidogus with help of Tanya who find the ancient texts and Li Mei who distracted the rest of warriors. The realms start to merging to revive the One Being. So Onaga launched his final attack, against the Elder Gods. Although they decide to not interfere in previous conflicts, this time they accept the challenge. The 6 God's of Creation, responsable for the creation of the 6 Kamidogus and also of the six realms (earth, nether, chaos, seido, outworld, edenia). They destroyed the One Being and this time they will do it again.

For the characters I put in there 24 characters, from every MK game. So, sorry if I killed some of your favorites. Also, I dont have the storyline for some characters, like those defeated by Deadly Alliance. Still dont know if they could help Onaga (possessed) or being Normal. I am talking of Cage, Sonya, Kung Lao and Jax. Most of Deception cast is killed.

- Kenshi - Killed by Hotaru.
- Havik - Killed by Kabal
- Nightwolf - his soul was trapped inside Netherealm. He seeks Ashrah sword to release.
- Bo Rai Cho - killed by Tarkatas, when Mileena give him a suicide mission.
- Noob-Smoke - Ashrah fight Noob and send him back to Netherealm. And Smoke was turned off by Sub-Zero.
- Ashrah - she purified herself and escapes from Netherealm
- Darrius - killed by Hotaru, before he becomes mad about order
- Kobra and Kira - they were too convinced about they abilities and go alone to face Onaga. No one has any news from them.

New Characters - Six Elder Gods of Creation
- GAIA - she created Earthrealm, the perfect realm with gates everywhere. She is the mother of every god of earth and it was her that helps Raiden fight against Shinnok, many years ago. She was the power of the elements.
- SHINNOK - he is the original god of Netherealm. But Shinnok did not accept to create a realm of dead souls and sorceres. So he tried to dominated the perfect Realm, the Earth, but Gaia interfered. Shinnok was in the Netherealm after MK4 and was released by the other Gods. They need him to destroy One Being.
- KAOS - the god of Chaosrealm. He founded the Chaos religion, and order did not mean anything to him. The kaos always should exist.
- EVE - Goddess of Outworld, a realm of the different races. Onis, Tarkatas, Vampires, Reptiles, Shokans and Dragons. She believed that Onaga with his army could control the different races. But Shao Kahn destroyed the balance when killed Onaga.
- SEIDO - the god of Orderrealm. The main city of the realm has his name on it. Seido likes order in all, like all the citizens. It is him that gives the order to the government to kill Hotaru.
- JERROD - I always thought about Jerrod being a god. Originaly, the Edenian race would live in Outworld, but Jerrod did not accept and created a sixth realm. But since no one was capable of reign over it, Jerrod becomes a Edenian human and ruled the realm. He married with Sindel and have a daughter called Kitana. Later, he was killed by Kahn...

From MK1

- CAGE - no story yet.
- RAIDEN - the Dark One.
- LIU KANG - ressurrected
- SCORPION - the Gods give him a dark mission. Kill Raiden for the crimes commited. Raiden decided interfere a lot with events, challenge the Gods when decided to fight with the Deadly Alliance.
- SUB-ZERO - Hotaru captured him and locks him in the Castle. Sub-Zero was saved by someone that he does not wait. Frost... Should he trust her again?
- SONYA - Like Ed Boon said We definitely see Sonya again in MK game. Any storyline for her?

From MK2

- KUNG LAO - I thought about the spirit of his ancestor came in contact with him and ask for help. His soul being tortured, some thing like that.
- REPTILE - in human form please. Onaga leaves Reptile body and occupied his original body found by Sindel. Reptile evolve again to human. But while he was possessed he discovers that his race still exists somewhere.
- KITANA- she was saved by Sindel and Jade and return back to the Edenia Palace. Kitana discover that Mileena destroyed a good part of his army send them to suicide missions against the Tarkata. Even Bo Rai Cho was destroyed. Kitana wants revenge.
- MILEENA - she return to Onaga's side after Kitana return. Of course she wants revenge. She convinced Onaga that everything that she did was for him. Baraka dont believe in her.
- BARAKA - he has control of the most savage army of Outworld. The Tarkatas are invincible.
- JAX - Dont know yet. I would like to kill him, but dont know how yet.

From MK3

- SINDEL - she located the original body of Onaga and when she was to destroy it, Onaga appeared and occupied. To Sindel the only thing to do was run. But Sindel will have some surprise when someone of the past returns.
- STRYKER - I like him a lot. I think that, since Jax, Sonya, Kenshi, Cyrax was missing in Outworld, the Special Forces hired Stryker to located them and bring them back.
- SEKTOR - In Japan, Sektor finished the Tekunin clan. The only thing that its left is to collect fighting data from powerfull warriors. Sektor goes to Outworld to collect data from the Savage Tarkatans.
- KABAL - He forget the Black Dragon when discovers the real plan of Havik. Revive Kahn. Kabal still wants revenge for what Kahn did in the past with him (the squad attack during MK3). Kabal kills Havik. Well but the real Kahn still exists and Kabal goes after him.
- JADE - I thought that Jade's past should be connected with Tanya. Not only enemy, traitor, this thing. Maybe sisters, I dont know.
- ERMAC - he did (or not) release the souls of the Earthrealm warriors. He still will help them, but something is bothering him about the realms merging.

From MK4, MKDA and MK Deception

- TANYA - still evil, but when she was in Edenia library she discover something about her father and the past. A thing that could change her destiny.
- FUJIN - Fujin is divided. The Earthrealm Goddess asked him to defend Raiden against Scorpion. But another God ask him to aid Scorpion in the mission in change of a position as an Elder God. What he will choose?
- LI MEI - Li Mei betrayed her comrades. But she was not confused. Li Mei listened stories that Outworld, before Kahn's invasion, had a really Good King. The Dragon King with a powerfull army that protected everyone. She believe that something is wrong with Onaga's wish to dominate all. She will discover it.
- FROST - She was badly damaged and Sub-Zero take her to an temple in Outworld. She was left in a sarcophagus. But instead of death, the coffin restores her power and life. Also, in that Frozen Catacombs, Frost discovered the real reason of her existence and origin. She helps a confused Sub-Zero escapes.
- HOTARU - Hotaru betrayed the people of Seido. The realms are merging and it brings chaos to the perfect civilization. But Hotaru still helps Onaga, believing that he will bring Order to all the existence. Nothing more matters for him, only order.
- DAIROU - Dairou was shocked when he was called by the Orderrealm Governement itself. The mission was to destroy Hotaru, that allow the fusion with the realms. In exchange, his crimes would be forgotten.

What do you think?