Punishing Gray Raven (Global) | Lucia Crimson Abyss (Alpha) hidden story unlock

Starting from the first battle, you'll get to control Roland, and from there you need to defeat all 3 corrupted before the other 3 construct fighting against the corrupted died, basically save all 3 construct WITHOUT ANY ONE OF THEM DIED, then get close to Lucia. At that point, you'll be fighting aginst the construct, kill all of them and end the stage. Then in the next one, where you'll control Lucia in stealth mode, don't let your enemies find you, sneak past all of them all the way to the finish point and you'll unlock the hidden story which connected to the stage where we fought against Alpha where you first started in the game.