The lantern archon stands as the least of the archons, the celestials of Mount Celestia. The students of the Mount, the squires, the the lantern archons are the first step of a Celestia petitioner wishing to transition, not into eventual merger with the plane, but rather into acting in its name.
Indeed, lantern archons are the transformed results of those petitioners which other archons identify as far more eager to serve on behalf of the plane than eventually become one with it. Such selected petitioners are, when of the proper development, brought before the Hebdomad where, if approved (as nearly all are), their form is transformed into that of the lantern, and sent back to Lunia to begin their existence anew.
Generally peaceful to outsiders, lantern archons are among the most inquisitive and social of the archons, given that part of their charge is to better get used to interacting with mortals in their new forms. Part of their new nature, after all, is said to purposefully deprive them of physical form, forcing them into an utterly new existence to better get them to internalize their new nature, to set them blatantly apart from mortals and lead them to learn new forms of interaction with them. Indeed, a large part of the duties of the lantern archons, simple as they may be — messenger, watchman, tout — are to either slowly accustom them to the ways of planar beings, or to grant them more familiarity with others of their new kind.
Lantern archons are far from pacifistic bystanders, though. While not extremely powerful, or even threatening, in large groups they can be quite the danger. Other archons, unlike the fiends, prefer to keep them out of combat when possible, but at times they are reluctantly called to service, via summoning rather than physical transit whenever possible. Indeed, most of their combat training is provided via summoning, allowing them a means by which they can grow accustomed to their new powers and how best to use them in near-total safety.
Lantern archons have a very simple appearance, resembling little more than a ball of light about two feet across, glowing about as strong as a torch (weaker if the archon is injured), and of any color in the spectrum. The color of a lantern archon is the only convenient way for a mortal to tell them apart; while they're hardly as unique as fingerprints, they are at least a constant for any given one.
- Planes of Law - Monstrous Compendium, pp.4-5
- Pathfinder Bestiary, pg.20