If you want them to just stand still and let the player talk to them you can just make a static box around them.
If you want them to move you should make a character controller. Now if you also want Dark A.I to work with it then you should make 1 controller, add the npc mesh as a child to the controller. Then make an ai entity. Every update make the controller move towards the ai entity, you must make sure the ai is set up correctly so the controller can keep up and wont get stuck, that is the major problem but it should work as i have tried it myself. Or you could just program your own ai into the controller.
Lucy in the
Sky with
Diamonds
