Uncanny X-Men: First Class - Knights of Hykon

The world trembles as the sky begins to boil! Professor X attempts a desperate rescue mission on the Starcore One satellite, but a threat from galactic legend is waiting! Who are Burning Moon, Cloud Runner, and Sky Song, and how are their fates tied to the X-Men? Earth faces destruction as the mutant heroes battle an unstoppable enemy... The Knights of Hykon! (All this and Nick Fury too!)

Collects Uncanny X-Men: First Class #5-8.