Monadic devas were a kind of angel and members of one of the three orders of the devas, the others being astral devas and movanic devas. The most patient of devas and with a firm appreciation for balance, monadic devas served as stewards of the gods and oversaw the Elemental Planes and the Ethereal Plane.
Devas appeared as human-like men and women[note 1] of extraordinary beauty or handsomeness with two magnificent feathered wings emerging from their backs. In contrast with their astral and movanic deva cousins, monadic devas had muscular, even bulky bodies, as befitted their strength. Their skin was dark brown, their hair was jet black, and their eyes were green and piercing.[note 2] Monadic devas stood around 6 feet (1.8 meters) tall, but particularly mighty examples could grow to much larger size.
Devas were averse to clothing; when they must adhere to mortal custom, they donned simple loincloths or other coverings.
The order of monadic devas was politically equal to the orders of astral and movanic devas, and there was no rivalry between them. Although the orders might sometimes bicker over differences in personality, they always cooperated.
Monadic devas served as stewards and servants to the gods. At their bidding, they watched over the Ethereal Plane and the Elemental Planes, including the Paraelemental Planes. Rarely, they were even commanded to undertake missions into these planes, thanks to their immunity to the effects of the Elemental Planes. Additionally, they were charged with protecting the Upper Planes from invasion, and in this role were the commanders of the agathinon warriors who patrolled the borders of the celestial realms.
Movanic devas who pleased the gods in their roles were given an opportunity to ascend to the stage of monadic devas. Likewise, a monadic deva of exceptional achievement might be granted the opportunity for promotion to astral deva. Some monadic devas, however, were quite content to remain in their current celestial roles.
Their long watches over the Elemental and Ethereal Planes gave the monadic devas a nigh-limitless patience and a deep appreciation for balance, more than any other deva. Thus, the majority of neutral good devas were monadic devas. They were also the most stoic by a long way. Yet they could grow bored of their watches, and saw battle as a much-needed and much-enjoyed diversion. No deva would knowingly deal peaceably with evil beings, but those of non-lawful bent sometimes dealt with neutral beings. They were strong-willed and fearless.
Each monadic deva wielded a long and sturdy metal rod empowered as a +2 weapon or a +3 rod of smiting or a +3 mace of smiting. It could strike or pierce a foe up to 10 feet (3 meters) away. It dealt greater impact damage to foes armored in metal and creatures made of stone or other solid materials. It functioned only for its owner and never ran out of power. They had no need of any treasure or wealth, nor even clothing.
Monadic devas loved battle more than any other deva. They used their great strength much more than their agility or speed. They favored charming any elemental opponents before rushing in to harry their remaining foes with powerful swings of their maces. They could not be surprised in battle and were hard to flank.
Monadic devas possessed all the powers, protections, and traits common to devas and to other angels, and many more of their own. They were immune to injury from mundane and minor magical weapons.
Delivered from death, monadic devas were naturally immune to all death magic, whether from spells or other powers. They were also immune to the draining of various forms of life source, such as by undead. 
Monadic devas were at home in any environment. They were at ease in all the Inner Planes—including the Elemental, Paraelemental, Quasielemental, and Energy Planes—being utterly immune to the traits of those planes, and furthermore they were immune to all forms of fire. They could breathe freely, no matter the conditions, similar to using a necklace of adaptation. They also possessed a power like the spell charm person or charm monster that applied only to elementals but worked at will.
In addition to the common spells of devas, monadic devas were also reported to cast a hold monster applying only to elementals and project image, later considered to be hold monster applying to all creatures and mirror image. Later, it was reported they could cast atonement, commune, consecrate, create food and water, cure serious wounds, daylight, death ward, dispel evil, dispel magic, divination, ethereal jaunt, hallow, holy aura, neutralize poison, prayer, protection from arrows, and raise dead.
When a deva died on the Prime Material plane or the Elemental planes, all parts of their body, what clothes they wore, their maces of smiting, and their other possessions vanished completely. Only their material body was destroyed, while their immortal spirit returned to their home plane. It took ten years to regain the power to manifest a corporeal form. If they died on any other plane, then they were destroyed utterly.
In 1369 DR, a group of six monadic and astral devas, led by Ariziel, was dispatched to capture the Winged, a dark planetar cast out from Celestia for failing Torm. The devas could not overcome the Winged, and found themselves captured in turn. They were turned into fallen devas and forced to fight in the gladiatorial arena of the Winged's master, the Thayan wizard Dennaton, where they eventually perished.
Queen Morwel of the eladrin was allied to a powerful brass dragon named Ronothere. Through him, she lent military aid to the cause of the archomental Zaaman Rul in his resistance against Imix, and this aid included a squad of monadic devas.
- ↑ The Monstrous Compendium Planescape Appendix for 2nd-edition D&D states that devas appeared as male humans, suggesting that they were only male. This was corrected in Warriors of Heaven, which on page 40 states that, contrary to the popular view, devas could be either gender. It explains, "Previous claims that all devas were male probably grew from the tales of explorers new to the planes who happened to see a few males and jumped to the wrong conclusion." The Monster Manual and Fiend Folio for 3rd edition only state that they appear as humans, but the Fiend Folio artwork presents the movanic deva as female, confirming that devas can be of either sex in 3e as well.
- ↑ The appearances of devas have been switched in each edition. In 1st edition, in Dragon #63 and Monster Manual II, monadic devas have a silvery-white coloration and muscular builds. In 2nd edition, in Monstrous Compendium Planescape Appendix, they have a dark coloration and muscular build. However, artwork for Monster Manual 3.5 edition also gives this appearance to the astral deva. Finally, in 3.5 edition, in Fiend Folio, monadic devas retain the dark coloration but are not explicitly given the muscular build. Meanwhile, movanic devas gained the silvery-white coloration in the 2nd- and 3.5-edition sources. This article uses the consistent combined description of the later 2nd- and 3.5-edition sources, and won't even get into the 5th-edition deva.
- ↑ 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 1.12 1.13 1.14 1.15 1.16 1.17 1.18 1.19 1.20 1.21 1.22 1.23 1.24 Allen Varney, ed. (June 1994). Planescape Monstrous Compendium Appendix. (TSR, Inc.), pp. 6–7. ISBN 978-1560768623.
- ↑ 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 2.10 2.11 2.12 2.13 2.14 2.15 2.16 2.17 2.18 2.19 2.20 2.21 2.22 2.23 2.24 2.25 2.26 2.27 2.28 2.29 2.30 2.31 2.32 2.33 2.34 Eric Cagle, Jesse Decker, James Jacobs, Erik Mona, Matthew Sernett, Chris Thomasson, and James Wyatt (April 2003). Fiend Folio. (Wizards of the Coast), pp. 55–56. ISBN 0-7869-2780-1.
- ↑ 3.00 3.01 3.02 3.03 3.04 3.05 3.06 3.07 3.08 3.09 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 Gary Gygax (July 1982). “Featured Creatures”. In Kim Mohan ed. Dragon #63 (TSR, Inc.), pp. 6, 7.
- ↑ 4.00 4.01 4.02 4.03 4.04 4.05 4.06 4.07 4.08 4.09 4.10 4.11 4.12 4.13 4.14 4.15 4.16 4.17 Gary Gygax (August 1983). Monster Manual II 1st edition. (TSR, Inc), pp. 42, 43. ISBN 0-88038-031-4.
- ↑ 5.0 5.1 5.2 5.3 Christopher Perkins (April 1999). Warriors of Heaven. (Wizards of the Coast), p. 40. ISBN 0-7869-1361-4.
- ↑ Christopher Perkins (April 1999). Warriors of Heaven. (Wizards of the Coast), p. 39. ISBN 0-7869-1361-4.
- ↑ 7.0 7.1 slade et al (June 1995). Encyclopedia Magica Volume III. (TSR, Inc.), p. 1033. ISBN 0-7869-0187-X.
- ↑ Julia Martin, Eric L. Boyd (March 1996). Faiths & Avatars. (TSR, Inc), pp. 34, 76, 129. ISBN 978-0786903849.
- ↑ Sean K. Reynolds (2002-05-04). Deity Do's and Don'ts (Zipped PDF). Wizards of the Coast. pp. 10–15. Archived from the original on 2016-11-01. Retrieved on 2018-09-08.
- ↑ Beamdog (November 2013). Designed by Philip Daigle, et al. Baldur's Gate II: The Black Pits II – Gladiators of Thay. Beamdog.
- ↑ Eric Jansing and Kevin Baase (March 2007). “Princes of Elemental Good: The Archomentals, Part II”. In Erik Mona ed. Dragon #353 (Paizo Publishing, LLC), p. 50.