The god stone is the living soul of a god trapped in the mortal realm. The mortals now had a weapon, as the god's soul's presence allowed channelling in the mortal realm without the necessity of gods being physically present. Humans rebelled against god's iron ruling and - armed with the god stone, and the threat of annihilation from this new power of the Splitter -the gods left the mortal plain and retreated the god's plain.
Since that time the god stone has caused, and ended, many wars, as it is an extremely powerful object, capable of feats of channelling mortals cannot achieve alone. It is said to be able to produce any effect the user can imagine, including retrieving souls from the twin gods of Death.
There have been few known wielders of the god stone, as it is a dangerous object that is known to corrupt its users. A few have ignored its consequences to gain godlike power, and have suffered greatly for it. The Black Wind was thought to have been a user of the god stone, and its power corrupted them into an ethereal monster. The last known user was Gaaveikur, a famous channeller who was noted for saving Norheim from the effects of the Black Wind when he invented warding stones, and with the help of the god stone erected walls around most major cities and settlements. As with any of long term wielders, Gaaveikur was corrupted to madness. His death was not documented and it is believed that he still roams the continent.
Mortals are not equipped to handle the power of gods.
Because of its dangerous nature, the Horse Tribe king at the time, Heiður III ordered a sealed tomb to be made to house it, until its secrets could be unlocked and used safely without the ill effects. The god stone sat safely in this tomb at Blackcastle