The Candles of God are a small cult, officially outlawed; they worship a fierce and jealous deity of fire whom they believe will soon come to rule the world and cleanse it of the unrighteous. They seek to speed up that process.
They keep their membership strictly secret; any given member will know, perhaps, four or five others at most. Their beliefs are spread through myriad poorly-typeset tracts and pamphlets distributed to their members by a leader, known by the code-name Quicklime. The Candles adhere to a strict set of moral principals- sex and alcohol are only to be engaged in on certain, ritual days; money is to be donated to the cult or to the poor; Thievery, fighting for any purpose other than the advancement of the faith, and eating uncooked foods are all completely prohibited. Members often react violently to anyone who even unknowingly violates their morals.
The cult seeks to overthrow the corrupt, decadent order of society and replace it with the glorious reign of their god. They will stop at virtually nothing to obtain their goals, but their favorite weapon, fittingly, is fire. Most often, they operate through arson, using magic or simple explosives to kill or destroy the properties of those who have offended them, leaving cryptic warnings about the decay of society in the ruins. They save the full force of their wrath, however, for public killings, often wiping out entire crowds of people in an instant.
It is for this, a tactic which they call “Illumination”, that the Candles are truly dreaded- an operative will infiltrate a crowd and begin to cast a very long and complicated spell. Aside from their almost-undetectable muttering of the spell under their breath, there is nothing to draw suspicion to them. Nothing, that is, until the spell is cast, and they and everyone in a hundred-meter or so radius is consumed in a vast, fiery explosion. The Candle, and most people within the explosion will be killed instantly, and fires often spread to surrounding buildings, doing even more damage
Some time later, a threatening note will appear nailed to a door or wall near the site of the blast as the Candles claim responsibility and lament the decay of society, promising the advent of their Utopian reign.
Naturally, this sort of tactic is rarely used, as it takes a great deal of magical training to prepare a candle for the “Illumination”, and the spell can only be performed once. Most often, they attack prominent figures- rulers, war heroes, politicians- making a public appearance, to wield a double blow to public morale and generate more notoriety for their cause.