Tome guardian

Tome guardians, sometimes incorrectly called tomb guardians, were tiny elemental creatures that were often summoned and bound by spellcasters to their most valuable tomes of arcane knowledge.

Description
Tome guardians varied in shape, some appeared humanoid, some took on other shapes, they all, however, were made out of living flames of the Elemental Plane of Fire and usually were between and  tall.

When these creatures were bound to an object, there were almost no indication of it, apart from faint dweomer radiation and warmth.

Abilities
Tome guardians were elemental creatures of fire and were immune to magical and mundane fire and absorbed it along with electricity, healing themselves. If they absorb too much fire or electricity, it temporarily increased their health, which lasted for about a day. This extra health gained could be channeled into its devastating fireburst ability, increasing its deadliness even further. Spells such as heat metal did not heal them; instead, the spell was merely absorbed by them.

The items that tome guardians were bound to were immune to any harm from fire elementals, salamanders, will-o'-wisps, and xag-yas. All and any attacks from these creatures on the guardians' objects could be absorbed by the guardians themselves. Tome guardians were also able to communicate with these creatures to guarantee mutual safety or survival. Tome guardians were unaffected by most enchantment nor charm spells, apart from geas, as well as by spells like dimension door and mind-affecting spells to psionics, which were considered to be an attack by the guardians.

Cold-based magic and abilities were very effective against tome guardians, but the water was practically useless against them. When someone attacked the item imbibed with a tomb guardian, it remained unarmed as an invisible shell surrounded it, part of the guardian itself; however, these attacks dealt full damage to the guardian.

The guardians could only be dismissed via a successful dispel magic spell and no other way.

Personality
From what little was known about these tiny elementals, they never attempted to communicate with other beings but could understand common. When they were bound to an item, they had only one goal in life, to guard it. The bounding magic also made them blindingly fearless.

Combat
When the object inhabited by a tome guardian was touched or attacked, the elemental creature made its presence known. It never attacked the object's owner and always focused its attention on creatures that were trying to consume the object, such creatures as bookworms.

Tome guardians' most noteworthy and favorite attack is a fireburst. This offensive only ability was accessible by a tome guardian three times a day and made up for its limited use by its sheer unavoidable power. Fireburst was a scorching flame of white color generated by a guardian in a thin, less than an inch in diameter stream. This white flame never missed and penetrated the target's armor, clothing, and shields. To make this attack even more devastating, fireburst could be "fired" through a mental link of a psionic assault or a communication attempt. That applied to any mental or psionic abilities, spells, or enchanted items. The stream of fire penetrated the target's defenses and skin and dealt internal damage setting the target's blood to boil for a moment. The only way to avoid a fireburst attack was to be immune to fire and heat. If the target survived the internal flames, they could be rendered unconscious for 20 to 50 minutes by the system shock of their bodily fluids boiling.

If unable to create a fireburst, a tome guardian generated tendrils of fire to whip at its opponents with. These attacks were not particularly powerful but always set aflame any flammable item or material they touched.

Ecology
Not much was known of these creatures' behavior or activities in the wild as most have only encountered them when bound to the items by magic. The binding was done to tomes of magic knowledge most often, even though it was possible to have tome guardians be bound to other items. Tome guardian binding could coexist with other protective magics, such as runes or glyphs. There have been stories about more than one tome guardian being bound to a single item, but these telltales have never been corroborated.

Sages theorized that on the Elemental Plane of Fire, their home, the tome guardians were friendly with most of the plane's elemental creatures. It was unknown if tomb guardians were completely different creatures, just a smaller variety of regular fire elementals, or a stage in their life cycle.

They were sentient beings and had true names, as was evident by the summoning spells used. The summoner needed to cast an ensnarement spell first and the blinding spell with the object to be guarded being within sight. Surprisingly enough, tome guardians did not resist the binding and did not mind the task given to them. When the bonding happened, the tomb guardian appeared to merge with the object and disappear into it with no trace but faint radiation noticeable via infravision. The guardians could only be bound to one object and, if the desired item consisted out of separatable parts, only one of them could be bound to.

Tome guardians could be trained to create its powerful fireburst while staying out of combat and remaining within the item. For example, a sword with a trained tomb guardian bound to it would be able to protect firebursts upon the owner's command. If tomb guardians were bound to enchanted items that produced fire or electricity magic, those items stopped functioning as the guardian fed on that type of energy.

If forced from their items via dispel, tome guardians assumed their natural shape and, eventually (between 20 and 40 minutes) faded back to the Elemental Plane of Fire. While they were unbound, they were attracted to fire sources, the bigger, the stronger the attraction was. Tomb guardians were friendly, when unbound, towards various elemental creatures of fire, guardian yugoloths, guardian familiars, and homonculi. Overall, Tome guardians were considered to be solitary and peaceful creatures, with only xeg-yi who they hated and attacked on-sight.

Sages agreed that tome guardians did not care for treasures while on Prime Material Plane and likely fed on fire, heat, light, and even feeding on the heat from the things and enemies they set ablaze. When they died, they exploded into a wave of hot air and left behind nothing but ash.

Usage

 * The dust left behind by a dead tome guardian could bee used in creation of oil of fiery burning or smokepowder, possibly other fire-enchanted items.
 * If a tome guardian were to die close to a ring of fire resistance, the wave of heat they released strengthened the item's enchantments.
 * Flame tongue and similar enchantment weapons could be ignited using the tomb guardian's fireburst attack even though that was extremely dangerous.
 * Some of the fireburst daggers found in the Realms had tomb guardians bound to them, utilizing their fireburst ability as an enchantment.
 * The spell scroll of burning hands could be scribed using ink that was created, in part, using tomb guardian's ash.

History
An ancient spellbook Jaluster's Orizon, had one of the tome guardians bound to the item, still defending it circa 1357 DR.

Circa 1367 DR, a tome guardian was bound to an account book that belonged to Jannaxil Serpentil, inside his bookstore, Serpent Books & Folios in Waterdeep.