Thornir Alekeg
Albatross!
OK, here are my 2 cents.
First off, as a bit of control over the potential power of this item, when it absorbs a new type of ring, it needs time to assimilate its new power, so it cannot use the new power for one hour per caster level of the power.
Second, as the ring gains sentience it starts to desire more and more powerful rings. It is no longer satisfied with a ring of Feather falling , and therefore leads the bearer into greater danger in an attempt to satisfy its own craving for power.
First off, as a bit of control over the potential power of this item, when it absorbs a new type of ring, it needs time to assimilate its new power, so it cannot use the new power for one hour per caster level of the power.
Second, as the ring gains sentience it starts to desire more and more powerful rings. It is no longer satisfied with a ring of Feather falling , and therefore leads the bearer into greater danger in an attempt to satisfy its own craving for power.