Disciple Squads are the fighting elite of the renegade armies of the Lost and the Damned. These fighters have willingly embraced the terrible powers of Chaos. Whatever their origin, such men have become hopelessly tainted and are fanatically loyal to their new masters. They are quite noted for looking like Chaos KKK's cause of the pointy hats and all, but they are probably modeled after Torquemada from Nemesis the Warlock. They sometimes accompany the leaders in command of a Renegade Command Squad.
Renegade Disciples are essentially WS3 BS4 renegade infantry, and come with the Fanatic rule to help get them some better leadership. Equipment-wise they’re much like a standard Imperial Guard infantry squad, able to take a single special and a single heavy weapon team, though the rest of the squad can have either autoguns, shotguns, or pistols and CCWs. Their base cost is very reasonable at 35 points, though much like the Marauders, adding onto the squad is fairly expensive, at 10 points per body (which only averages out to 8 points per model on a 10-man squad, assuming 5 points for the Champion upgrade). If you want to make them tougher, they have the option to buy Carapace Armour for 20 points for the squad, meaning it’s far more cost-efficient on large squads.
Everything above basically carries over into 8th edition along with a WS buff/change - now they hit on a 3+ in both CC and with shooting attacks! How's that for nifty?
9th edition gives them another nudge, with a max size of 15 bodies, +1 S in close combat and they never suffer negative modifiers to their Ld for morale tests. Almost makes up for the shit-kicking Renegades and Heretics took in the changes from 8th to 9th.