Before we start...

Name: Evan Hansen

Age: 27

Aliases: Rookie, Rook, Deputy, 'Dep

Looks:

Weapons:

M4A1 (Used when he was in the Resistance)

P226 (40 S&W Version, used by SWAT)

The scene opens up with a truck on a road somewhere in Montana, and someone is heard and then after getting to somewhere a tree falls onto the pickup truck and it kills everyone inside, except for one of them, whose body was missing. As there was one survivor.

In Teyvat...

Someone is looking at some kind of town or small city, and he has someone else with him, and she's floating and is wearing a white and pink-ish outfit, and then they heard something. It later shows Evan grabbing his M4 and then he inspects on how much ammunition is inside his SIG. Then he moves on with his M4 pointed at nothing and he scans the area, then he encounters some Hilichurls, so he puts them down with three bursts. Then he sees the same person from earlier, fighting off some enemies, so he puts the M4 on his back and he pulls out his SIG as the boy was about to deliver the final attacks to the remaining monsters and he heard gunshots.

https://youtu.be/3NJuVvMUj_s

Evan: You okay?

Paimon: Who are you?

Evan: I'm Junior Deputy Evan Hansen. Most people would call me Deputy or Rookie by my colleagues.