These weird creatures are believed to come from an alternate Prime Material Plane. Known to sages of old as Eaters of Magic (with reference to the hakeashars which was a more vicious form of nishruu), they feed on magical energy and are greatly feared for the damage they can do.

Nishruu appear as silent, amorphous bodies of red, breathable mist, lacking visible organs or features. They glow, pulsing regularly as they drift about, and can seep through finger-width cracks. They will always move toward the greatest concentration of magic within 60 feet.

Combat: Aside from their effects on magic, nishruu inflict no damage to objects or beings. Physical attacks and nonmagical fire affect this creature normally, and hits are automatic if an attacker is enveloped by a nishruu. Magical cold- and fire-based attacks inflict half damage when launched from outside the monster, but they cannot form within a nishruu. Furthermore, those magical attacks from outside the nishruu are absorbed after inflicting just one round of damage.

Nishruu ignore physical attacks, moving fearlessly and relentlessly toward sources of magic. Mind-control spells and illusions do not affect them. Any spell (other than those mentioned above) cast at a nishruu is absorbed by it, having no effect except to give the creature life energy equal in hit points to the damage the spell normally inflicts. A nondamaging spell gives a nishnruu extra hit points equal to its spell level.

Chargeable magical items are drained of 1d4 charges upon contact with a nishruu, and if contact is continuous, the drain occurs again at the end of every second round. Nonchargeable magical items have their powers negated for 1d4 rounds after contact. If used when in contact with a nishruu, the effects of potions and scrolls suffer a delay of 1d4 rounds after contact ceases.

Artifacts become inoperational at all times while in contact with a nishruu, and for one round after contact ceases. Spellcasters of all classes who are enveloped by a nishruu lose one memorized spell (determine randomly) at first contact and one per round of contact thereafter. Each time a loss occurs, the spellcaster must make a successful saving throw vs. breath weapon or become feebleminded (as the spell) for 1d4 rounds.

Habitat/Society: Nishruu are solitary creatures that are not native to the Prime Material Plane. They cannot voluntarily transfer magical spells or charges to another being. Salt, both rock and sea, is deadly poisonous to nishruu – a handful of flung salt typically inflicts 2d10 points of damage upon a nishruu. Salt can therefore be used to confine or herd such creatures, for they will not willingly come into contact with it.

Ecology: Nishruu feed on magic, drifting endlessly and relentlessly about in seemingly aimless searchings for it. These creatures can actually detect the presence of magical energy within 600 feet or so, and they will always move toward the most powerful, plentiful, or nearest source of magical energy. No upward limit for energy absorption is known, nor is a nishruu known to have starved from lack of magic. Most sages believe that sunlight and moisture may also sustain the beings.

When a nishruu is slain its body dissipates, losing luminosity and hue and appearing to sink into the ground. Any magical item within its body area when it is slain, or any magical weapon slaying it, even if no longer within the body, receives a magical bonus of 1d6 additional charges (or a second use in the can of items that can normally be used but once, such as arrows and scrolls). Potions, memorized spells, artifacts, and items that do not have charges will not be augmented.