Aetaos'Rau'Keres
Aetaos'Rau'Keres is the most feared and powerful Lord of Change in the immaterium and is also one of the most powerful daemons in existence. Keres is insane, even by daemon standards, due to Tzeentch shackling him with numerous types of warpfuckery, to the point where he feels nothing but utter rage. Such is his insanity that only apocalypse cults dare summon him, because once Keres enters realspace, he will murderfuck every living thing on the planet he is on, neither caring if he's killing loyal cultists or the enemy, until nothing is left.
The kicker to him is that Keres' true purpose in Tzeentch's grand schemes and his origins are his most closely guarded secrets and nobody but Tzeentch know what they really are. If anyone or anything comes close to finding out the truth about him, he will personally appear before seeker and obliterate him and the planet he is on, just for good measure.
On tabletop, Keres clocks in at 999 points, Tzeentch's sacred number, and has LV4 mastery. He has a slew of special rules, including the ability to bounce back psyker powers, summon daemons, and his trolltastic "Boon of Chaos" template ability which forces units under it to pass a toughness test or be turned into a gribbly mass of tentacles.
