Oooh...what a fun topic!
Here's my take on the Chaos powers.
Khorne The Blood God
1Red / 1Black / 7colourless
Legendary enchantment creature - god
9/9
Double strike, haste, indestructible.
As long as your devotion to red and black is less than nine, Khorne is not a creature.
During each combat phase any creature able to attack must do so.
For each creature placed into a graveyard, place a +1/+1 counter on Khorne.
TAP: Move any number of +1/+1 counters from Khorne to any other creatures.
Nurgle, The Plague God
1Black / 1Green / 7colourless
Legendary enchantment creature - god
8/10
Deathtouch, indestructible, swampwalk
As long as your devotion to black and green is less than eight, Nurgle is not a creature.
Sacrifice a creature: all creatures you control gain deathtouch until the end of the turn.
TAP: deal X damage to target creatures or players, where X is your devotion to black
TAP + 2 colourless: all creatures you control gain swampwalk until the end of the turn
Slaanesh, The Pleasure God
1White / 1Blue / 7colourless
Legendary enchantment creature - god
8/10
Flash, indestructible, lifelink
As long as your devotion to white and blue is less than seven, Slaanesh is not a creature.
3blue: Gain control of target creature this turn. That creature gains haste.
1colourless: Tap target creature.
TAP: Counter target creature spell.
Tzeentch, The Change God
1Black / 1Blue / 7colourless
Legendary enchantment creature - god
*/9 Tzeentch's Power is equal to your devotion to blue.
Flash, indestructible, protection from multicoloured
As long as your devotion to black and blue is less than ten, Tzeentch is not a creature.
Whenever a multicoloured spell is cast you gain 1 Life.
Sacrifice a creature you control. Gain X colourless mana, where X is the creature's casting cost.
1Black / 1Blue: Tzeentch gains flying until the end of the turn.
TAP + 2 blue: search your graveyard for any creature and put that creature directly into play tapped.
TAP + 2 black: target creature or player take 3 damage.