The Corpse Maiden set has 3 pieces in it: A dress, a collar and a scarf.

The set also has 5 custom animations.

1. Carrion Swarm animation
2. Silence animation
3. Exorcism animation
4. Attack 1 animation
5. Attack 2 animation

However, the way they are hooked up to the items is weird:

1. Carrion Swarm -> Dress of the Corpse Maiden
2. Silence -> Ghastly Scarf of the Corpse Maiden
3. Exorcism -> Dress of the Corpse Maiden + Wick Collar of the Corpse Maiden + Ghastly Scarf of the Corpse Maiden (requires all 3 to work)
4. Attack 1 -> Wick Collar of the Corpse Maiden
5. Attack 2 -> Dress of the Corpse Maiden + Wick Collar of the Corpse Maiden + Ghastly Scarf of the Corpse Maiden (requires all 3 to work)

The Exorcism and Attack 1 animations seem to be swapped. Exorcism should be bound to the Collar only, and Attack 1 should be like Attack 2, bound to all 3.

It should be:

1. Carrion Swarm -> Dress of the Corpse Maiden
2. Silence -> Ghastly Scarf of the Corpse Maiden
3. Exorcism -> Wick Collar of the Corpse Maiden
4. Attack 1-> Dress of the Corpse Maiden + Wick Collar of the Corpse Maiden + Ghastly Scarf of the Corpse Maiden (requires all 3 to work)
5. Attack 2 -> Dress of the Corpse Maiden + Wick Collar of the Corpse Maiden + Ghastly Scarf of the Corpse Maiden (requires all 3 to work)

As of now, if you just equip the collar, DP uses her default animation and one of the 2 custom animations. When you equip all 3 parts, she only uses the 2 custom animations.