All takedowns are the same, only each one is specially designed for a certain playstyle, they always have at least 3 steps:

1. You run at a target, screaming, they are now frightened of you. 
2. You take 2 hard knives and stab into the target's two shoulders, cutting them off. 
3. You then stab the target's legs and bite their head.
4. You rip the head off as you cut off the target's legs and stare at him. 
5. You look around, your eyes are now blood red and insane. 

This takes a Full Action and intimidates everyone around you who "sees" you, making them frightened.