Call faithful servants was a conjuration spell that summoned up to four celestials to the caster's side. It was a spell commonly used by celestials who were spellcasters, and it was also employed by Harper paragons.
Up to four lantern archons, coure eladrin, or musteval guardinals were called to the location of the caster, where they remained to serve for up to one year as guards, soldiers, spies, or toward whatever other holy purpose the caster desired.
The spell could be cast multiple times, but there was a limit to the maximum number of celestial servants at one time, depending on the power of the caster. If the spellcaster summoned servants over this maximum, the longest-serving celestials were returned to their home plane.
With the exception of Harper paragons, it was not possible for a non-celestial to cast this spell successfully.