Heaven

    As has been noted previously, the angelic social hierarchy is primarily based on the strength of the individual's āyus, with the more powerful angels ascending to higher Choirs than their weaker brethren.  Many angels who attain enough power will choose not to ascend and prefer instead to remain in their current Choir for a time.  Should the power disparity continue to grow, however, the angel will generally opt to ascend eventually.
     There are seven Choirs of angels, each sharing several traits, skills, or other characteristics that tend to distinguish its members from other Choirs.  The three lowest Choirs (Erelim, Parasim, and Sarim) rarely contain angels who have sufficient āyus to have Awakened to an individual identity and named themselves.  They are also the most populous of Choirs - the higher an angel ascends in Heaven, the fewer peers he has among his new Choir.  Lower Choirs genese regularly (at least during wartime when numbers must be replenished), which helps account for the relative scarcity of individuality among their ranks.

Seraph/Seraphim

Seraphim are the elite Choir of angels and hold the highest positions of power and authority in Heaven.  They are tasked with the oversight of the immortal plane as well as the safety of its inhabitants, angelic and blessed dead alike.  Seraphim were most often in direct contact with God during the early days of existence when the deity was regularly amongst them, and most were given specific tasks and duties to perform by God Himself.  Without exception, Seraphim appear as six-winged humanoids and are considered the most beautiful of all angels, even by the superior standards of the immortals.  Beyond that shared trait, there is little if any consistency in their choice of garb, coloration, armament, or temperament.

Dominions

Second in strength only to the Seraphim, Dominions occupy most of the command positions in the Heavenly Hosts not filled by their higher brethren.  There is little consistency in their garb and armament, as any angel to have achieved this Choir has long since thrown off the vestiges of conformity that so mark the lower ranks.  The only exception is the preference for and near universality of an extra pair of wings - only a handful of Dominions since the beginning of time have foregone the four-wing appearance of their brethren.

Powers

Powers are usually tasked with mid-level command positions in the Heavenly Hosts, and they are typically responsible for keeping the peace amongst the blessed dead.  Even in Heaven, conflicts and difficulties arise amidst recalcitrant mortals that have to be dealt with to ensure peace and harmony in the immortal plane.  Powers are notorious for their general lack of humor, which some scholars have blamed on having to deal so frequently with eons of squabbles between the blessed dead.  Angels of this Choir often prefer to appear as a gaseous haze, like smoke given humanoid form.  Their wings are usually asolved, but many forego the use of wings, especially those who eschew humanoid form altogether and instead resemble an amorphous cloud.  Those who prefer humanoid form (whether solid or gaseous) often arm themselves with weapons and armor of all sorts (sometimes influenced by the combat styles of the mortal souls they interact with), while whose who remain insubstantial usually just use weapons created from their own āyus during combat.

Cherub/Cherubim

Angels who have not yet attained sufficient strength to Awaken will generally do so once they ascend to the Choir of Cherubim.  A Cherub without a name is considered a rarity, almost as uncommon as a Parasim or Sarim who has one.  Cherubim are the first ranks of the elite warriors of Heaven, and as such they garb themselves in armor made from true metal at the Anvil of Heaven.  This offers them a tremendous protective advantage in combat against lesser immortals and is virtually a requirement to survive a battle against a stronger one.  Metallic weapons offer similar advantages when on the offensive.  Most Cherubim choose to craft their own weapons and armor by hand, under the guidance of the Dominion blacksmith Dem and his assistants.  The most popular style of armor among Cherubim consists of form-fitting platemail with minimal protection at the joints to prevent restricting their motions.  Cherubim are rarely found without a bow, but there is little consistency in their choice of close-quarters weaponry.

Erelim

Erelim (and some Parasim) are typically the aerial warriors of Heaven and as such are almost never to be found without their wings asolved.  Some have even expressed a preference for flight over any land-based movement and will only set foot on the ground of Heaven when absolutely necessary.  Erelim appear mostly as winged humans garbed in tightly fitted folds of white cloth, occasionally with flowing, colored tabards that may be discarded during combat.  While close-quarters aerial combat is almost inevitable in a war among immortals, Erelim are typically armed with bows and take advantage of the freedom offered by the skies to attack from great distances.  When hand-to-hand combat is required, they resort to a variety of swords, daggers, axes, and other bladed weapons that are easily wielded in flight.

Parasim

Augmented by the ranks of the Sarim, Parasim make up the bulk of the ground-based soldiers in battle.  Beyond their general choice for weaponry, there is physically little to distinguish Parasim from their Erelim brethren.  Like Erelim, they are humanoid and rarely seen with their wings dekinted, but Parasim often opt to appear with leathery armor and arm themselves with long swords, spears, and other polearms they create from their own āyus.

Sarim

Weakest of the angelic Choirs, Sarim are conversely generally among the strongest healers.  There are notable healers amidst the higher Choirs, to be sure, but a Sarim of only middling strength will have greater healing abilities than any higher angel who has not made such healing a focus.  Indeed, most of the best healers among higher Choirs were originally Sarim who ascended.  Their combat skills are rudimentary compared to their higher brethren, and their primary role in battle (aside from healing) is akin to what mortal commanders refer to as "cannon fodder".  Sarim typically appear as slender humanoids, often almost elven in appearance, garbed in flowing white robes and armed with close-range weapons they create from their own āyus.  The presence or absence of wings seems to be mostly an afterthought unless specifically ordered one way or another by a ranking angel.