First things first, I decided to randomly determine which of Games Workshop's Ruinous Powers my army would follow. I rolled a D10, with 1-2 meaning Khorne the Blood God, 3-4 meaning Slaanesh the demon of hedonism and excess, 5-6 Nurgle the plague God, 7-8 Tzeentch, the god of magic and trickery, and 9-10 being unaligned.
A 4 means my army is dedicated to the sensual and depraved Slaanesh. Iiiiiinteresting. Not the Power I necessarily would have chosen for myself, but that's why we're doing things this way, to mix it up.
The next step then was to pull up a PDF of the old "Realms of Chaos: Slaves to Darkness" book, and use the warband rules there to determine the composition of my Dragon Rampant army. I won't end up with a nice, balanced force but I should end up with something fun.
First up, my general. A D100 roll determines that my general will be human, and a second D100 roll determines that, in Warhammer terms, they're a Level 10 Warrior. So a fighter-type, not a wizard or spellcaster. Easy enough. A few more dice rolls determines that my general has a Bestial Face, which causes fear in those who face them and a bonus to Willpower.
So I'm thinking my general is going to be a Single Model Unit of Elite Foot with the Fear special ability tacked on, and "Charmed" as his Leader trait. Resistant to magic, he wades into the midst of combat, hacking down enemies and sending the survivors fleeing in terror. I have a model in mind but we'll get there later. For now, that's 8 of my 30 points taken care of.
Next, I make three rolls on the Retinue chart and come up with Chaos Thugs, Beastmen, and a special! We'll come back around to that last one.
Chaos Thugs/Marauders/Raiders are (in my head at least) a disorderly, bloodthirsty rabble barely kept in check by the general's force of will. Well that's Dragon Rampant's "Bellicose Foot" right there! I don't think I want to add anything on, so we'll leave that at the basic 4 points.
Beastmen I imagine as being much the same as Thugs/Marauders, but tougher and harder to kill. I decided to treat them as Bellicose Foot with the "Extra Shiny Armor" upgrade, for 6 points.
Finally, the special. The "Other," the 100 on the D100 roll. A few more dice rolls determine exactly what it is that joins my warband, and it is...a cockatrice. Ooh! Now there's something different! What do we do with that? A cockatrice isn't as big and nasty as a hydra, chimera or dragon, so I don't think the Greater Warbeast profile is quite right, but let's call it a Single Model Unit Lesser Warbeast. Both historically and in the Warhammer lore, a cockatrice has a petrifying gaze ability that turns foes to stone at a distance. The Flame Attack upgrade, granting the Lesser Warbeast a ranged attack, would model this nicely. And the wide, batlike wings on the 1990 GW Cockatrice model also call for the "Fly" fantastical ability to be added on, so let's call that another 8 points.
So let's see, that puts us at 26 out of our planned 30 points. Hmmm. I could throw in another unit of Thugs/Marauders for 4 points, or I could pull 2 points off an existing unit and add in a unit of Chaos Warriors as Elite Foot. I don't really have any ranged capacity at present and I don't have a spellcaster present either, which could hamper me in future games, but on the other hand, I knew going in that this would not be a balanced force. I'll think about it and get something squared away.