After he had been selected to enter the Sacred Promissory—after the Minister of Preparation had used the Promissory’s Forerunner machines to alter his genes and enhance his mind and body

-Halo: Fractures, pg. 153 (Halo: Shadow of Intent)

	Of all the Forerunner technologies the San’Shyuum had tried to unlock, genetic engineering had proved the most difficult. This was largely due to the fact that the Forerunners had refined their bio-enhancing tools and procedures for their own physiologies, not for other sentient creatures. Coupled with San’Shyuum taboos against doing anything that might further jeopardize their already limited ability to reproduce, research into this particular brand of Forerunner magic was completely ignored by all of their ministries save one: the Ministry of Preparation.

-Halo: Fractures, pg. 182 (Halo: Shadow of Intent)