Alron Stone

The Alron Stone is the Demon Stone which imprisons Alron the Astral Walker.

Naming of the Stone
The Demon Stone... containing Alron... known as Alron Stone

Alron Imprisoned
After Mirdon and Varlah were stripped of their power as Guardians and exiled, they derived a plan to lure Alron into an ambush, where Varlah could use her Demon Plane powers to imprison Alron inside a Demon Stone.