Vastu Purush Mandala having 45 Devtas and Asuras.
Yama – the Maintainer: The energy field adjacent to Grihakshat, in the South direction, has been termed as Yama. Yama means self control, moral duty. The power which binds the world in laws is that of Yama. That is why Yama is also called as the cause of death.
Since the physical body has been attained under a law (principle), it has also to be left with in a law. However, it is mentioned in Rigveda and Atharvaveda, that if Nairitya (South-West) releases from its Pash (control) then Yama resurrects and gives back the life. Nairitya means ancestors’ place. So, for those, having high strength of ancestors, even the laws get changed.