After the events that transpired in the world of heroes, the group is soon met again by Spectra Force with word that a powerful weapon known as the X-Blade is being forged in the past and is a target of the Kaima. In an attempt to stop them, they traveled back to the past where they each encounter three youths named Terra, Ventus and Aqua. By following these three, they saw that their lives were never going to be the exact same again.
Following Terra was the Spectra Force along with Shizuo, Rainbow Dash, Lemon Zest, Gajeel Redfox and Isaac Clarke. Following him, they saw darkness in its purest form as they were lead astray by a man named Xehanort. By trying to find the darkness, it lead them to do bad things and even killing Terra’s Master Eraqus. Upon arrival to the Keyblade Graveyard, they battled Xehanort with all they had. But they soon realized the old man was more clever than he appeared as it was a plan to plunge Terra into darkness so he could send his own heart into him, taking over Terra’s body and heart.
The Dimensional Heroes Followed Ventus as he searched for Terra. As they traveled with him, they were beset by creatures known as the Unversed, creatures derived from wild emotions. They even met old friends like Yuri, Estelle and Flynn. But one of the bigger things was being pursued by a boy in a mask named Vanitas. Clashing with him a few times, they soon learned that Vanitas was separated from Ven as a way to forge the X-Blade. After being defeated by Ventus and Medaka, he shed his mask and forcibly joined with Ven. But the main heroes dove into Ven’s heart and battled him inside it. Though they slayed the evil boy, this was not the end as Ven’s heart fell into a deep sleep, whether it will awake or not is still unclear.
Finally, The Shining Hope Squad went with Aqua as she tried to find her own answers to how to combat the darkness if not with light. As they traveled, they grew closer to each other and Aqua. Even meeting old faces like X and Zero. They encountered the boy Vanitas as he tried to be rid of them all so his plans could go uninterrupted. Eventually, they confronted him and Xehanort in the Keyblade Graveyard where Hope, Aqua, a small mouse king named Mickey and Twilight were left to face off against a Ventus possessed Vanitas with the X-Blade. But they stood little to no chance against him. Twilight, even with broken armor, stood against Vanitas as he tried to attack. But her courage to protect her friends manifested into physical form as a keyblade. She fought back against him with Aqua as they drove him into a corner, destroying the blade and freeing Ven.
After these events, Ven was moved someplace to sleep peacefully as Aqua, the only one left, decided to join Hope since he and his team were the only friends she had left. She even took Twilight on as an apprentice. After capturing Hakai, the last of the executives, they soon learned that the classic capturings were a trick to distract them from the real plan, elimination of the Yo-kai Watch. They decided after that to return to a certain town: Springdale.