Faerie fire

Faerie fire was a Evocation or Alteration spell that outlined a target.

Effect
Faerie Fire always seems to have caused a glowing lining around targets in a selected area. At some times of the state of the weave the spell also caused the targets to also be easier to hit, and once it was a damaging spell that slow targets. The targets that have been effected and so show the glowing outlines are easier to see at a distance.

Coponents
Other than the usual vocal and somatic components  one version needed Foxfire.