After Elsword went into Wally's Secret Lab in Elder, he faced a whole army alone in order to save Aisha from Wally's captivity.
including getting bombed down by missiles of Wally's. He recognized that he does not have any chance against a hopeless battle, he went after Wally hoping that if he killed him his army fall would apart afterwards. All of the sudden it turned out that Wally was half Nasod like Raven. Elsword recognized that fact too late and got stabbed by him falling to the ground while Aisha was crying after him.
Elsword woke up in a world where only him and a person looking like him existed. The other "Elsword" called himself the "Rune-Slayer Class"He told him that this world he was in was his subconscious and the current Elsword is dead.