Demon deacons are level 97 combat Summoning familiars. They belong to the Demon group of familiars, and currently share the special move, Ring of fire, with two other demons: demon executioners and demon brawlers. It is the magic damage variety of the group. This group of familiars also share the unique trait of being aggressive; they will automatically find and attack new enemies of the type you are currently attacking (though you must be in combat for their aggression to activate).
The Ring of fire scroll enables the Ring of fire special move for Demon brawlers, deacons, and executioners. Using any of the three pouches on a summoning obelisk creates 10 scrolls.
Ring of fire
Ring of fire is the special move for the demon class of familiars, which is a magic based area of effect attack that hits all monsters within 4 tiles of the familiar for up to 1065 damage.
This article on a Summoning familiar has an associated dialogue page. Click here for a transcript of possible conversations with this familiar.
When in a God Wars Dungeon encampment, this familiar will treat non-slayer creatures as the same type of enemy, thus engaging any of them in combat automatically. If you attack a slayer creature (i.e. spiritual mage), however, they will begin to attack that class of monster too.