> Sartar (Tentacles pre-release edition) goes further and claims that
> the Owner of the Rune can do "anything potentially imaginable" with
> their Rune.
That's been changed slightly since then. It currently reads:
Owners of Runes
Each of the Core Runes originally belonged to a member of the Celestial Court, the assembly of Old Gods who ruled the universe between its creation and the Gods War. Two types of deities were recognized within this assembly; the Powers and the Elemental Rulers. The Celestial Court was destroyed with the coming of chaos and the Core Runes are now owned by Great Gods.
The Owner of a Rune can do anything within the ambit of that Rune. For example, Orlanth is the Owner of the Air Rune; Orlanth and his worshippers can use the Air Rune to fly, control all aspects of their breath, shatter stone with a loud shout, call down thunder against a foe, throw lightning, summon a hurricane, make the sky clear of clouds, and so on. Orlanth and his worshippers can potentially do anything with air, storm, or violence.
Other entities have a more limited access to the potentiality of the Rune. For example, Urox has the Air rune, but is only the master of the Desert Wind and the violence associated with it. Humakt possesses the Truth rune, but can only use it for oaths and honor â€" not for general knowledge.
A few gods (or their specialized subcults) can use a Rune to command a few limited powers of another Rune. For example, the subcult of Barntar can use the Air Rune to plow their fields (something normally associated with the Earth Rune). That power is exceptional and a result of the mythology of that god or subcult; it is outside the conventional ambit of the Rune.