According to one account, the Tremas Master's Trakenite body was destroyed after attempting to seize the Warp Core, which reduced him to his decayed state.
History[]
At some point, the Tremas Master discovered the existence of the super weapon the Warp Core, how it was bound to the painting The Scream, and plotted to capture it.
The Master elected to steal it from the art gallery it was situated at, but he completely misjudged its rage when he inadvertently awakened it while in the progress of the theft. It proceeded to strip the body of Tremas from him and destroying it, which left the Master reduced to his decayed form, before it went back to sleep. (AUDIO: Dust Breeding)
Legacy[]
The now Decayed Master was inspired by the taste of the Warp Core's power, and proceeded to lay out a more elaborate scheme to capture it and seize its power on its origin planet Duchamp 331. When he retold the fate of his previous body to the Seventh Doctor, the Doctor pitied him. (AUDIO: Dust Breeding)
The Master would eventually become a Deathworm Morphant, enabling him to survive his execution by the Daleks and possess the body of the human Bruce Gerhardt. (TV: Doctor Who)
When he ultimately emerged from the Eye of Harmony for good, after several previous attempts to escape, the Master had been returned to a Morphant-augmented version of his original decayed form, (AUDIO: Mastermind) in which he was ultimately killed by the Ravenous before being resurrected and regenerating into the Reborn Master. (AUDIO: Day of the Master)