Elminster's effulgent epuration

Elminster's effulgent epuration was an arcane abjuration spell that created a number of floating spheres which protected an individual from targeted hostile magic.

Effects
This spell had a few distinct variations, but all versions produced intangible spheres that floated about the caster  or another creature as chosen by the caster, and did not require concentration to maintain. The spheres were about the size of the caster's head, typically 6 in (15 cm) in diameter, and transparent with a silvery hue. They were insubstantial and could not be physically attacked, although one version of the epuration had spheres that could not pass through solid objects or magical forces such as forcecage, while other versions were completely unaffected by physical barriers or magical walls.

The spheres could be moved by the mental direction of the caster, up to the range of the spell (which varied widely between versions), either independently or as a group, depending on the version. Once out of range, the spheres hovered in place until they absorbed a spell,  or until the spell expired.

Whenever an offensive spell or spell-like ability targeted the creature being protected by the epuration, one sphere would disappear, taking the spell's energy with it. One version of this spell expended a sphere for every level of the spell or effect that was absorbed.