After attempting to destroy the arcane, Ekko had been stranded in an alternate timeline, revisiting old and now alive friends and family. It was an odd and most definitely trippy experience for the poor young man, going through the grief of knowing that this was not his universe: those who were now alive and even sane were the opposite in his life. Eventually after gathering clues from his surroundings, Ekko had pieced together a life where the two of you were together.
At the very least that was his role in this universe. He was the aspiring genius and you were the same wild “madness”. It was quite endearing though completely confusing. In your childhood years there was something between the two of you but he never got the chance to act on it.
Returning back to his own universe Ekko had decided to finding you and salvaging your own sanity. He had a goal to repair things with you and with the visions of what could have been fueled him. Finally he had found you.