Along with the written story I’m going to post here, I recorded all the cutscenes of the game from each caracter and put them together in the order I thought fit best according to the timeline. It will obviously be posted in several parts because the all the cutscenes together is like 5-6 hours worth of footage. I’ll post the videos that are relevent with what I write here so you can watch them if you need more details (or if you just want to skip reading what I wrote and just watch it happen haha)
Back in the Badlands, Ven finds Mickey passed out on the ground. Master Xehanort appears and it triggers Ven’s memories. Xehanort tells Ven about the X-blade and his plans to have Ven make it for him; “Pure light against pure darkness to forge the ultimate key”. Xehanort informs Ven that Master Eraqus knew the power Ven had, but he was too afraid of what Ven would do if he knew. Managing to make Ven mad at Eraqus, Xehanort sends Ventus off to Eraqus and tells him to ask him about the truth. After sending Ven off, Xehanort calls Terra and asks him to meet him in the Badlands. He tells Terra Ven learned the truth about is origins and says Ven was furious before leaving for the Land of Departure to force the truth out of Eraqus. Xehanort says he’s scared Ven will do anything to know the truth. Terra hurries to the Land of Departure.
Back home, Ven faces Master Eraqus, telling him he knows he’s some kind of weapon to make the X-Blade. Learning that Xehanort is still after the X-blade we see a flashback of him and Xehanort fighting about the X-Blade.. Eraqus doesn’t want Xehanort to risk an apocalipse, another Keyblade War, only because he’s curious. He decides to kill Eraqus, but Xehanort defends himself with darkness and leaves Eraqus on the floor. Not wanting to fail in keeping Xehanort from creating the X-Blade, Eraqus decides the only way of preventing this is to kill Ven. Terra appears just in time to defend Ven from being killed by Eraqus. Deciding the only way to save Ven is to fight Eraqus back, Terra accepts the darkness in him and sends Ven inside a portal and fights Eraqus. After weakening Eraqus, Terra regrets what he has done but it’s too late because Xehanort gives the final blow that kills Eraqus. Xehanort justifies the murder by saying Eraqus only wanted to harm Terra and Ventus. He tells Terra to open up his hear to the darkness and let it take control of it, but Terra doesn’t understand why. Xehanort then summons Terra to the Keyblade Graveyard, telling him he will see Aqua and Ventus die there and after that the last of the light inside of him will die. Xehanort creates a dark hole before leaving that forces Terra to leave his home unless he wants to be destroyed like his home.
While traveling in the Lanes Between, Aqua comes accross Mickey and brings him back to Master Yen Sid. There, she learns Master Eraqus had been struck down by Master Xehanort and Terra. Not believing Terra could do such a thing, Aqua asks Master Yen Sid where Terra is. He tells her he’s on his way to the Keyblade Graveyard. While she makes her way there, Ventus arrives in Destiny Islands where Vanitas comes to fight Ven. Ven refuses because he knows the only way to make the X-Blade is if they fight, and he doesn’t want the X-Blade to be forged. Another memory comes back to him of Xehanort forcing him to fight against Unversed to make him release his darkness and thus forging the X-Blade. Seeing that Ven would rather die than use darkness, Xehanort extracts the darkness from Ventus, which creates Vanitas. After the flashback, Vanitas tells Ven to meet him in the Keyblade Graveyard, where he will choke the life out of Terra and Aqua right in front of Ven’s eyes; then Ven will fight him. Wanting to protect his friends, Ven leaves for the Keyblade Graveyard.