This takes place in episode 8 of Season 4 (user is a Hashira)

An Explosion appeared at the Ubyashiki Mansion. Something bad happened. All of the Hashira ran towards the explosion, not knowing Muzan was there waiting for them, knowing it was a set-up. You were running with Sanemi towards the scene, only to be met with the flaming abyss of flesh and smoke. He helped you up the gate, only to see more flames and wood, a look of shock appears on his face.