his tomb is expeptionally weird and creepy.

I wouldn't expect anything less for a saint. I learned about the following from "Hellboy (2004)" of all things. Emphasis mine.

Reliquary

A reliquary (also referred to as a shrine, by the French term châsse, and historically also a type of phylactery) is a container for relics. A portable reliquary may be called a fereter, and a chapel in which it is housed a feretory or feretery.

Relics may be the purported or actual physical remains of saints, and may comprise bones, pieces of clothing, or some object associated with saints or with other religious figures.