ideas for human characters, Cyborgs/android, Demons, and Vampires ...
Bounty Hunters
Bounty Hunters go around, and find anything human, Neko, living dead, and thing that has a bounty on there head and turns them in to collect pay. They also hunt demons and vampires.
Cyborg/AndroidCyborg

Android

They have the same objective to kill, thats all androids do, unless you changes there programing to something different. Cyborgs are not as deadly, they still have some human feelings, so they only kill if you threaten them.
Demon 
They are ruthless killer they will kill and challenge anything they can take on, they will even kill each other give then chance. They mostly love killing humans, vampires, and other demons.
Vampire 
Come out at night to drain the blood of human, demon if and only if, they can get their fangs on there neck. They try to stay away from hunters for this reason, reason being that they will murder them in a heart beat.