Durandal

Cavendish possesses Durandal which is a named sword.

As proven by Durandal (whose rampancy is most prominent throughout the story), who often gives the player what he calls "philosophical tirades," affected AIs are often very reflective.

Durandal refers to himself as being rampant still during the second game, indicating that he has not reached this stable state (or is just lying, which is also possible).

Durandal/Thoth in Marathon Infinity describes the legendary W'rkncacnter as having distinct identities.

It could be suggested that Durandal achieved some measure of stability, but this is debatable.

The AI Durandal is obsessed with discovering the secrets of the Jjaro and believes they possess the knowledge of how to escape the universe and thus become God-like.

There is also a theory that this treatment actually helped keep Durandal's rampancy in check, by depriving him of new stimuli that would contribute to his growth.