The Masters Hunters
it is not known who or what the Masters Hunters are. Speculations and documents discovered on Planet Place and Koken speak of a group or force that caused the demise of the Pree
and forced the Uni to flee.
Some suggest that the Master Hunters are somehow connected to the Guardian of Earth.[1]
[1]Workgroup Olympus has compiled a list of "Cosmic Guardians" and it appears that many older civilizations and societies have one.
However it appears that only the one of Earth perished.
The Dark One declared the Guardian of Earth a misguided event and declared that the Narth Supreme has always been the real Guardian (see The Guardians secret)