Unlike other members of their race, they do not have enough power to project an image to the physical world in order to be able to interact with it. Instead, they possess objects or creatures, gaining a body in the physical side, but this method makes them practically half-mazoku as long as they stay that way. This means that they are vulnerable to simple physical attacks such as non-magical weaponry or elemental (air, fire, earth and water) shamanistic magic to an extent; although thanks to either their tough bodies or other unknown factors, they are still able to resist weaker attacks such as Freeze Arrow. Also, this condition enables them to utilize their magical potential to its fullest without the fear of damaging their ego and themselves. Their intelligence is severely limited, however, which makes them unable to use any save the simplest shamanistic spells, such as Flare Arrow.
Being little more than mindless beasts of destruction, lesser demons are used as cannon fodder in mazoku armies, to keep the weakest foes occupied, or to create a diversion. Some more powerful mazoku are not above using them as last-resort sources of shōki (negative emotions), wounding and killing them to feed upon their agony, gaining a little extra power.
Except for weaker elemental incantations, most offensive magic is capable of harming or even killing a lesser demon, including less powerful astral spells such as Elmekia Lance or black magic spells like Blast Ash.