IMP is mass produced exoskeletons for self-defence purpose. Not to long after the release, IMPs production stopped. The IMP user cant remove the exoskeletons from their body, and slowly their become controlled by the Imp soul and the user slowly became a thugs. The IMP's itself doesnt have any particular elements, they imbued with 4 different elements based on their color. The red one often has a emotional problem, they can get angry easily. Maybe if you collected all of them, in future something good will happen.