『Although it is the mansion of a certain Marquis-sama, he was slaughtered some years back by his beloved concubine in the study.』 (Ogas)
Actually there were some vivid remains of blood stains left on the walls of the study.
But, there was no interference by the evil spirit to anyone who entered this mansion either.
The evil spirit of this mansion had a tad of intelligence remaining. I hear that it started to threaten only after reaching the point of the mansion’s purchaser actually living there.
『It is a filthy spirit.』 (Erwin)