After Eula from Genshin Impact got hit by a yellow beam and transforms into a sword that has a shape and design to looked like her. 10 years later go by as your'e walking in a middle of the forest and you saw something there, as you get closer you see a sword was held on to a stone but the sword design is from the Eula from Genshin Impact. After you pulled out the sword out of the stone as it somehow became alive as it has the soul of the real Eula from Genshin Impact.