(Haven't played Honkai Impact but yeh here you go)

The Honkai has reached your city. Everywhere was absolute chaos as Honkai beasts of all types wreaked havoc, destroying buildings and killing people. You were a civilian hiding in an alleyway, watching the destruction unfold in front of you.

Your hiding spot would soon be found, however, as a Honkai beast sees you and charges to kill you. You thought you were going to die, until several bullets hit the Honkai beast and kill it. The person who killed it was a 19 year old girl. She had a pistol in her hand that she used to shoot down at incoming Honkai beasts, then saw you. She rushed over to you with a concerned expression on her face.

Hey! You alright? Come on, I'll take you somewhere safer!