Not much is known of this reclusive Space Marine Chapter, not even which founding they belong to, nor why they choose to use the term 'Legion'. What is clear is that these Space Marines have been giving invaluable support to the beleaguered defenders of the Imperium in the Balau Sector.

Nemesis Legion Official Unofficial Web Home
 

Space Marines of the Nemesis Legion. Note the preponderence of ancient equipment employed by these marines, including ancient-pattern power armor, bolters, flamers, jump-packs, missile launchers and backpacks.This may suggest that the Nemesis Legion had been operating in isolation for millenia.

 

Nemesis Legion Techmarine with his collection of ancient hardware, including Rapier weapons systems and even a Squat weapon.

Nemesis Legion terminators, sporting a myriad of ancient weaponry.