Complex sentence: The Asgard inform him that about the Ancients and how they were an alliance of Four Great Races (the Ancients, Asgard, Nox, and Furlings), and that O'Nile's race was advancing to become the Fifth Great Race.
Split into simpler sentences: The Asgard inform him that about the Ancients and how they were an alliance of Four Great Races. The Ancients, Asgard, Nox and Furlings and that O'Nile's race was advancing to become the Fifth Great Race.