As the war progressed, the Time Lords became increasingly aggressive and unscrupulous. Growing in desperation, they accessed a cache of forbidden doomsday weapons fashioned by the ancients of Gallifrey known as the Omega Arsenal. All were wielded against the Dalek menace save one: "the Moment". Moreover, they resurrected the Master, a renegade Time Lord and nemesis to the Doctor, as they believed him to be the "perfect warrior for a time war". However, after the Dalek Emperor gained control of the Cruciform, the Master deserted his post, used the chameleon arch to disguise himself as a human and escaped to a time period shortly before the end of the universe. Genetically a human, he escaped the destruction of all Time Lords as well as detection by the Doctor – who was unaware of his resurrection in the first place. The Master also remained ignorant of the latter phase and outcome of the war until he emerged from hiding, when he was told by the Doctor many years later.