Wizard's True Ring

The most powerful of magi can create what is known as a Wizard's True Ring.  The mage must be of at least of the fifteenth order of magic and spend several months working at his arcane forge to create his True Ring.
The prime purpose of True Rings, is to allow whoever wears the ring to know the location of any other ring that has been created by  its creator and to control any being that is wearing a ring he created. If worn by someone other than the creator,  the ring will do all it can to influence the wearer in order to return to its maker.
A True Ring will have a measure of arcane power equal to that of its creator. With this additional power the wearer of the ring can cast spells or summon beings. If the ring is touched to a mundane ring, the mundane ring will be enchanted and become a controlled ring under the power of the True Ring. If touched to a magic ring, the magic ring might resist to being enslaved by the True Ring. However if two true rings touch, they will both attempt to dominate the other until one is forced to submit.
A True Ring might have additional powers as desired by its creator. These powers if any are determined by the knowledge and abilities the creator possesses. A mage can only create an enchantment for knowledge he has learned. 
It has been observed that in making a True Ring, a mage will attempt to enchant it to give himself an increased chance at surviving obstacles and combat.  Other powers observed are invisibility, projecting an aura of fear, the ability to control various elements, just to name a few.
A True Ring is difficult to destroy. Dragon fire is one way. The other is to melt it in the same forge with which it was created. If either of these happen all of the power that was put into the true ring and any controlled ring will be reflected back upon the ring maker. All controlled rings will have their enchantments fade in a matter of days if not hours. A mage will do what he  must to prevent this.