The Deceiver is the most subtle and treacherous of the C'tan, the Star-God of trickery, lies, and manipulation. Where its brethren ruled through raw power and terror, the Deceiver — known also as the Great Deceiver and by the Necron name Mephet'ran — wove its dominion from cunning, playing the ancient Star-Gods and the mortal races against one another for its own inscrutable ends.
It was the Deceiver, legend holds, that engineered the great betrayal of the War in Heaven, whispering to the Necrons — then the flesh-and-blood necrontyr — the promise of immortality through biotransference. In casting off their dying bodies for undying metal, the necrontyr became slaves to the C'tan, their souls consumed to feed the Star-Gods' hunger. Yet in the end the Deceiver's own schemes turned upon it, for the awakened Necrons rebelled and shattered the C'tan, the Deceiver among them, binding its shards to their will.
Even fragmented, the Deceiver remains a thing of infinite guile, and many suspect it orchestrated its own imprisonment as merely another move in a game whose scope no mortal mind can grasp. It appears in whatever guise best serves its purpose, sows discord between empires, and delights in the fall of the proud. To bargain with the Deceiver is to lose before the first word is spoken — for every truth it speaks conceals a deeper lie, and every gift it offers is a snare.