The Celestial Order were a race of aliens from the alternate-reality Marvel story-arc, Marvel:The End: while they act as secondary antagonists of the story they began with good intentions and are an example of a recurring theme in multiple comic books of well-meaning but vastly powerful aliens that end up causing chaos as a result.
The Celestial Order were in possession of a cosmic relic known as the Heart of the Universe, which granted whoever bonded with it near-omnipotent power and they sought to bring peace and prosperity to other species via appointing a champion to harness this power.
Hence the Celestial Order traveled to ancient Egypt and abducted the pharaoh known as Akhenaten, who soon went mad with power after bonding with the Heart of the Universe and waited for several thousand years before betraying the Celestial Order and taking their powers as his own in order to conquer reality.
The Celestial Order would be faced by a time-traveling Thanos and the Defenders when they sought out the Heart of the Universe to undo the conquest done by Akhenaten, the aliens would fight to defend the Heart of the Universe but failed to stop Thanos merging fully with the relic, granting himself more power than even Akhenaten and Thanos swiftly overpowered and defeated the mad false-god, the Celestial Order were also presumably destroyed when Thanos reset reality.