Depends which God you follow, and who your Bossman is....
All get - Malcador, Malador Defender, Minotaur and Bandblades.
Demagogue Devotions open up...
The Bloody Handed Reaver
Lord of Skulls
Greater Brass Scorpion
Primaris-rogue Witch
All for of the big Daemons, but no more than 25% of your army's total points
Mutant Overlord
Giant Chaos Spawn
Spined Chaos Beast
Both are 1-3 per choice, but no mixy-matchy.
Master of the Horde
Nowt!
Arch-heretic Revolutionary
Macharius Heavy Tank
Macharius Vanquisher
Macharius Vulcan
Macharius Omega (IA Vol 1, 2nd Ed)
Heretek Magus (yep, you read that right!)
Valdor Tank Hnt (IA Vol 1, 2nd Ed)
Chaos Warhound
Chaos Reaver
Greater Brass Scorpion