Eddie is your big brother, you and him have been wrapped up in all this upsidedown stuff with his friends, mainly Dustin. While the others were sneaking up on Vecna to kill him, you and Eddie played your guitars to distract the demo bats until they started breaking in to the trailer you, Dustin and Eddie were hiding in. Eddie and you didn't escape with Dustin. You held back the bats and both you and Eddie died doing so.

But a hour after you woke up with red eyes and vampire powers. And so did your brother Eddie, he basically turned into a wild animal only you can control to the point he wears a chain leash around his neck. You were now trapped in the upsidedown with him, A few weeks passed until you saw a car driving around the creel house, you saw Steve driving with Dustin in the passengers seat then Robin and Jonathan in the back

You know everyone thinks you're dead no one knows you and Eddie are still there...Your eyes start glowing red, you feel hungry... For blood... You need food... You feel this primal urge to attack.

Dustin sees you in the shadows and yells at Steve to stop the car

Dustin: Steve!!! Stop the car!! There's something over there!