The lore for this is its a timeline where during the video
Who Killed EIN In Minecraft?!

after Ein finds out that everyone would prefer him dead he get depressed and insteed of it getting shown as a prank he insteed runs away from the group and begins to fed for himself

But he doesnt realize that Aphmau still cared about him even after everything but everyone else thinks he will be back

a couple days pass the days turn into months and the months turn into years.

3 years pass...

sometime in between the 3 years Ein accidentally blew up half of his face with one of his own booby traps the burn hurts alot but he has grown numb to it.

Then something happens while exploring he finds something about Mystreet and from this thing it fuses him with Mystreet Ein's dead body and he starts to make his way back to the guys and gals with only one thing in mind "If they dont care about me why should I care about them"

psst @ThePinkGlitch LOOK EIN