>>3781592
>e. I also don't really understand what the Heartless are supposed to be and how they really act. Like, are they just supposed to be like

I always thought that the purebloods were akin to the undead and consume whatever they can. The Emblem Heartless on the other hand act like whatever they were modeled after.

>What about who controls them
False Ansem/Xehnort's heartless controlled a few, while most act on their own accord and wander aimlessly.