After breaking free of Aku's control, and ensuring that he won't be able to control her anymore, Ashi inherited all of Aku's powers and fights back against him.
Jack: (realizes something) Ashi, you have all of Aku's powers!
Ashi: (gasps in realization) I do! (gets the sword and returns it to Jack) That means I can do this too! (creates time portal around herself and Jack)
Jack: (looks back to all his surviving allies nodding at him in realization one last time) Thank you, everyone. (Jack and Ashi disappear into time portal before Aku reaches them)
Aku: (scared) Oh no…. NOOOOOOOOOOOOOO!
Inside the portal, Jack looks around to make sure he made it, confirms in relaxation then ages to his actual age, his 70s, growing back his beard in the process, only longer.
Ashi: (notices in shock) Jack… you're aging…
Jack: (understanding this) It seems that time has finally caught up to me… But I can still finish this.
Ashi: (nods in determination) (holds Jack's hand)
Skip to past Jack about to finish off past Aku, who opens a time portal and sending him forward in time. Future Jack arrives and despite his new aged appearance, immediately ambushes the shocked Aku by throwing his sword into him in surprise then sprints to pull the blade out. After cutting Aku down several times, not giving him a chance to recover, Jack delivers the finishing blow by impaling Aku through the head, absorbing him into the sword and finally kills him by striking the sword into the ground, destroying Aku once and for all and preventing the bad future from ever happening. Jack and Ashi escape the exploding lair and Ashi collapses, about to fade out of existence.
Ashi: Without Aku… I would have never existed…
Jack: (sad) Ashi…
Ashi: (stroking Jack's face) It's okay, he can never hurt anyone ever again. Goodbye, wait for me. (disappears from Jack's arms)
Jack: (silently crying) ... I shall wait for you. My love.
Jack returns to his home, and though everyone is shocked at his new aged appearance, proudly reward him for fulfilling his destiny with a coronation to become the new emperor since Jack's parents still kept the same appearance in the time skip of "The Beginning" meaning his father is physically incapable of keeping the title. Jack accepts the new title in honor, dressing as King Jack in the ending of "Traveling Creatures" but still mourns Ashi and his allies of the erased future while chronicling his entire journey in the future. After the coronation, he wanders the forest alone with his thoughts, then sees a ladybug that reminds him of Ashi and stands over the edge of a cliff, erecting his sword into the ground in honor of Ashi's sacrifice while looking over the distance with a firm expression.
Guardian: (voiceover) The prophecy… is now complete… exactly how it should be.
The End