Rahs 'Tarn

"There is a cancer eating at the purity of creation. Beings augmented through science and artifice. Such creatures, if they can even be called that, are the basest offence to the natural order of our existence. These beings the humans call Spartans, my brothers knew them as Daemons. I know them only as the 'Tainted'. And it is by my hand that I will wipe their scum clear from the face of the galaxy"

- Rahs Tarn

In the wake of the Human-Covenant War there were many objections and concerns raised about the sudden appearance of augmented people in the galaxy, foremost among these being the surviving Spartans. Many, both within and without humanity, believed that the existence of these beings could present a very clear and present danger. Tales of the feats performed by Spartan personnel as nothing short of impossible raised very pertinent questions to the safety of Humanity and other races. Many saw their appearance as a sign that humanity was advancing its evolution to quickly, that they were playing as gods with their own existence. And for many ex-covenant groups they raised more damning questions about the nature of humanities purity of purpose and the path they were taking. For one Sangheili these were questions that had only one answer. Such beings were a threat and an insult and must be dealt with accordingly.

Rahs 'Tarn was a former Sangheili operative turned bio-terrorist who fought a long and brutal personal crusade against any augmented persons in the post war galaxy, mainly targeting members of the UNSC's Spartan Program. In his belief he saw these beings as corruptions of 'natural order' which he saw as the evolution of creatures through adversity and struggle as opposed to interference through science.

Rahs was born to a wealthy keep on Sangheilious and unlike many Sangheili displayed a keen and intuitive understanding of science, which made him something of an outcast in his races warborn society. He eventually went even further and trained as a healer, a highly dishonourable profession. Despite their many misgivings over this choice the Kadion of Rahs's keep recognised Rahs's unique talents and allowed him to proceed with his training.

Rahs couldn't hide from his races destiny forever and he was soon taken from his training and placed in the ranks of the Covenant military. Despite proving a competent warrior Rahs never gave up his love of science and continued to continue his training any way he could despite the stigma it placed on him. He would serve the Covenant faithfully in the final years of the war but it would be on the last few battle grounds of the war that his fate would be altered forever.

Rahs was present during the battle of Reach and bore first hand witness to the unmatched skill of the Spartan super soldiers. During the closing days of the campaign Rahs and his squad was able to best a group of Spartan's and were able to spirit one of the corpses away before the planet was glassed. Turning it over to the Huragok for examination Rahs remained behind to sate his own curiosity. He was shocked to discover that the spartans weren't human corpses brought back to life but augmented human's, enhanced through human science. However, before he could bring this knowledge to his superiors the Great Schism erupted and Rahs's discovery was lost in the conflict.

Returning to Sangheilious Rahs spent a long time pondering his discovery. Eventually he concluded that these beings were both a great danger to his race and an offence to what he saw as the natural order of evolution. So as the post war period begun in the wake of the Great War Rahs started his crusade to remove all augmented beings from the galaxy.

For years Rahs worked to understand his enemy, kidnapping and experimenting on humans to learn their biology and expand his knowledge of medicine.