It is a long standing debate over which Chaos God is the greatest. Khorne the god of blood and war, Nurgle the god of plague and pestilence, Slaanesh the god of pleasure, or Tzeentch the god of change.
All four gods have benefits and negatives the choice is yours who to follow.
Or is there a greater path to hold them all as equals and worship them together, does that give you greater strength or does it dilute the power?
Lets start with Khorne. he is bloodthirsty and his troops are just the same, at just over 20pts per model, they are fairly cheap for an extra attack and furious charge they are also able to have up to 3 plasma pistols in one unit. The daemon weapon for the lord is particularly devastating allowing up to 18 power weapon attacks.
But Khorne does not have the staying power of Nurgle who are toughness 5 making them alot harder to kill and effectively having two saves thanks to Feel no pain. they can be equipped like a standard squad and have both offensive and defensive grenades, their Daemon weapon can kill any creature
Tzeentch has the staying ability and killing power of both by having a 4+ invulnerable save so that even lascannons are not a threat to them and AP3 bolters means even the Power armour of Space marines is useless. however their disadvantage is high cost and slow movement having to be lead by a sorcerer champion who does have a force weapon (bonus)
Slaanesh has high initiative and multiple weapon settings allowing movement and a high number of shots or stationary firepower. They also have a weapon which strips the armour of Space marines. I don't know too much of Slaanesh so you will have to fill in the gaps
As for going "Black Legion" this is the path i have started to fall down, the increase in effectiveness outweighs the loss of power that each unit suffers from only having one or having normal marines with a banner for them as then the Tzeentch can give the Khorne a cover save while getting their Invulnerable, Nurgle chosen can infiltrate and stay around, the Tzeentch can whittle down any opponent before the Khornate close in and finish them off. It all works in Harmony.
Now you get your say.
Which do you think is best, or do you believe in uniting the Chaos powers for the greater evil.
[Update] You can now vote in the poll on the right hand side of the page :)