"You will have your feast of souls, and I will have the unlimited power I deserve. The Faceless Armies will see to that...and the humans, what can they do but burn?"
- Vilgax addressing Malefor and Bughuul.
Vilgax no Karrn (The Conqueror) is a Chimaeran warlord, who founded and commands the alien Faceless Empire. Vilgax's strange asymmetrical appearance is due to the fact that he mutated himself in order to become stronger, practically immortal, resistant to physical damage, the vacuum of space, and disease.
Vilgax was completely unknown to the UNSC or humanity until the late-mid 2100s, where he and his Faceless struck against Earth under request of Malefor and Bughuul . His being unknown was due to his covertness and his activity being reserved largely to the outmost fringe of the galaxy (although, the Chimaeran race was known to Boss Cass, whom sought their help in donation of the bio-engineered monsters for his own army).
Vilgax is a master of silence, as he has been able to amass a terrifying force of aliens without attracting the attention of many other advanced civilizations (all the ones that did notice he destroyed). He is infamous for his ability to strike with speed, silence, and immense force as well. He has crushed every civilization that he has encountered, and he is possibly one of the most threatening aliens in the universe.
Vilgax was born in the year 476 C.E, on the Chimaeran homeworld of Chimaer. Growing up, he had no idea what he wanted to become or what he wanted to do with his life. However, all this changed when a rival alien civilization known as the Tsar'el attacked his homeworld. After a mandatory draft, Vilgax entered the military. He rose through the ranks quickly as he took part in (and led) sequential victories against the invaders. Eventually, he was responsible for driving the invaders back into space, and hunted down their remnants to near extinction. It was here that Vilgax discovered his desire to destroy and crush his enemies.
Vilgax decided to take over the crushed remnants of his former enemies, and in his terrible cruelty, he oversaw their enslavement and torture. Vilgax ordered those in fighting condition to be experimented on, and mutated to the point where they no longer recognized their past existence. Vilgax and the Chimaerans broke the Tsar'el, transforming them into mindless abominations bent on destruction. This formed the backbone for Vilgax's new empire, of which he named himself lord.
He named his empire the Faceless. With his new empire, he crafted bio-engineered soldiers to add on to his numbers. Eventually, he held the largest empire in his sector of the MIlky Way Galaxy. He began conquering territory for his empire, planet by planet, civilization by civilization falling to the Faceless. Vilgax soon earned the title "The Conqueror" for his bloody campaigns across the galaxy. He became feared across the galaxy, as the bane of peace. Vilgax was legendary for his invention of lightning war tactics. This practically made him invisible, invincible, and unstoppable.
In the 2160s, Vilgax was contacted by two powerful beings; the Dark God Bughuul and the sorcerer Malefor. These two teleported directly to his personal carrier, the "Nhraxx Vuldai", which translates to "Chariot of God". Such was Vilgax's pride. The two dark beings requested that he lead an invasion force to Earth, for their own purposes. Vilgax, happy to pillage and destroy, accepted their request. He then began to send fleets to Earth's orbit, where they cloaked themselves to avoid detection. Then, they began to teleport troops and artillery planetside, therefore bypassing orbital defenses and taking the forces of Earth completely by surprise.
Vilgax, unlike many aliens, is utterly sadistic and cruel. Vilgax is one of the few alien leaders known who is actually enamored by destruction and war. He is extremely intelligent and calculating. Vilgax's goals are plain and simple; he wants the universe to be his. He is very power hungry, and he is always on the lookout for a new civilization to destroy.