types of spirits

In theory, every spirit is unique but theologians and adventurers a like have made efforts to classify the unclassifiable.
The easiest way to distinguish spirits from each other is by what they were created to do.

Messenger Spirits
Communicating their divine will is something all of The Nine like to do.
There are a few especially eloquent spirits that are primarily used as messengers, but Pretty much any spirit can be a messenger. They don’t even have to talk. If a spirit shows up and provides some aid or even just smiles at you that’s like “Good job, buddy!” from your god. If a spirit shows up and gives you the stink eye or tries to kill you that’s like “Watch it buddy!” from your god.

Soldier/Fighting Spirits
Any theurgists or favored souls that attains a degree of proficiency in the divine sphere of Spirit Magic can summon minor fighting spirits. These beings usually take the form of mundane animals with obvious supernatural enhancements.
Each of the Nine have a few more potent fighters they use to protect what is worth protecting or smite what is worth smiting. Many of these are humanoid, but that is hardly universal, some take the forms of dragons or other fantastic beasts
Maylar, Zarthus, and Hallisan are very martial gods that are fond of smiting their enemies, so they maintain a cadre of powerful spirits in reserve. On the other hand, all three of these gods would prefer their mortal followers kill their own enemies.
Mera is a peacenik and Nami is pretty laisez faire, so they use few soldiers spirits.
Korus actually utilizes the most specialist soldier spirits of all the Nine because there are many remote areas of natural splendor that he wishes to guard. Phidas and Khemra are also fairly likely to employ many guardian spirits.

Advisors, Teachers and Oracles
At the start of the Third Age when the human race was young, the Nine had many teacher spirits teach the humans things like writing, agriculture, animal husbandry and whatnot. Same goes for when the other races were young. Now there aren’t nearly as many teacher-spirits because it’s much easier to let mortals teach the next generation.
In modern times, Greymoria has the lion share of teacher spirits. First off, Greymoria creates new races quite often, so her newest children need someone to show them the ropes. Second off, she is the goddess of arcane magic and arcane magic is difficult often requiring one-on-one instruction. In most cases, if someone wants to learn arcane magic from a spirit, a price of some sort must be paid, usually in the form of a service to Greymoria's ideals.
Zarthus has a tiny number of spirits capable of teaching arcane magic. This is technically violating the spirit of the Compact , but Zarthus thinks it’s important that good moral people learn arcane magic and not just Greymoria’s followers. Nami has a few arcane spirits as well, mainly out of curiosity and because she doesn’t like being told what she can and can’t do.
Favored souls frequently have no idea who or what they are. In most cases, their divine patron periodically sends a spirit to check on their favored souls. At least once to explain to them what they are. Sometimes a favored soul ends up with a lifetime protector, friend, and mentor.
Priests that are very high ranking such that they make worldwide decisions for their religion can regularly expect visits from advisor spirits. A few governments that are very tight with one of the Nine, have advisor spirits regularly talk to kings and similar governmental leaders, but this is fairly rare. While Khemra doesn’t have a lot of spirit advisors, she has more than the rest of the Nine because Khemra is a bit of a micromanager.
Other spirits can serve as oracles providing warnings and prophecies. In most cases, the Nine prefer their mortal priests serve as advisors and oracles but spirits can step in when mortal priests can’t or won’t.

Questing Spirits
The whole point of a questing spirit is that defeating them is difficult but not impossible. A questing spirit can take the form of a large scary monster requiring mortals to show their mettle or they can pose challenges in the form or riddles or tests of morality.
A lot of legendary magical items or tomes or lore have questing spirits ensuring that only the "worthy" may access it, depending on which of the Nine created the questing spirit depends on their definition of worthy.
Most mortal priesthoods are given jurisdiction on who gets promoted to what ranks but in some cases, those seeking the very highest office must prove themselves to a questing spirit.
More often than not, questing spirits are created by the Nine to test their worshipers specifically. Maylar is the exception. Maylar loves to send questing spirits to test the mettle of all mortals whether they worship him or not.
At any given time there are at least a few dozen Maylar spirits wandering around inflicting misery until a hero takes them down. Unlike the rest of the Nine, Maylar actually doesn’t hold a grudge when his spirits are slain, at least not his questing spirits. They are supposed to be destroyed. Anyone who can beat them is truly strong and Maylar respects the strong, even when they oppose him. It’s the protecting the weak thing that bugs him.
After Maylar, Nami is the second most likely deity to send questing spirits to challenge random mortals but Nami prefers riddles and mental challenges over combat challenges and Nami's questing spirits are far less likely to kill the mortals they test, they usually just try to hinder them.

Punishment Spirits and Trickster Spirits
All the Nine have at least some desire to punish those who displease them. Greymoria considers 90% of all mortals to be deserving of punishment. Unlike Maylar’s questing beasts, Greymoria’s horde of spirit minions isn’t trying to make anyone stronger or serve any justified greater purpose, they are trying to inflict misery on death on mortals who don’t love and worship Greymoria as much as they deserve.
Phidas, Khemra, and Hallisan also have a small squad of powerful punishment spirits to hunt down law breakers who their mortal followers cannot seem to catch. Zarthus has punishment spirits to, but rather than attack the guilty directly, Zarthus spirits are likely to render aid to the guilty party's existing enemies.
Trickster spirits combine the concept of punishment and teaching into one as the lessons can be fairly harsh. It’s hard to get Nami truly mad, so I figure most of her punishment spirits would be tricksters. The other gods could employ tricksters as well. Zarthus likes to humble the proud and Maylar's tricks tend to be very brutal indeed.
Korus would send punishment spirits against those who despoil nature. Either the punishment spirits would kill or wound the offenders or blight the offender’s crops. The latter is sort of a nuclear option but it’s always on the table. That is why even most iron fisted tyrants try to avoid offending Korus.
Mera is the deity least likely to punish wrongdoers but she will withhold aid form those who displease her. Some Mera spirits are not above gloating.

Healing Spirits
Mera is the goddess of healing, so it is likely that she has more healing spirits than the rest of the Nine combine. Since most of Mera’s divine spell-casters have some sort of healing power, she usually deploys her spirits to remote areas where her mortal minions cannot go easily.
Mera's has many spirits that are dedicated exclusively to healing. Most of the rest of the Nine's healing spirits are multi-taskers such as advisor spirits with healing powers or warrior spirits with healing powers. The most notorious healer spirits are the extortionists in Maylar’s retinue. They cause disease with the left hand and cure disease with their right, for a price.

Nature Spirits
The Nine each have Dominion over some aspect of nature. Spirits can help with this. The sun and the moon are pretty self-regulating but Khemra and Zarthus could have spirits that can shine light in the darkness.
Hallisan can have spirits which bring minerals to the surface from the Elemental Plane though he prefers to set automatic processes into motion.
Phidas doesn’t need spirits to maintain the Barrier against the Void but he probably has spirits that try to kill Void Demons that sneak through, or at the very least warn people that demons are sneaking through.
Nami controls the weather. She has a huge army of spirit minions related to specific forms of weather. Thunder men, ice maidens, lightning men, etc. Nami doesn’t need a spirit to be behind every rainbow, shower, or heat wave, but if you see highly unusual weather such as blizzards in the middle of summer, one or more spirits are probably involved.
Korus could employ fertility spirits that can make the plants grow faster. Phidas and Hallisan can bestow life stones with power for a similar effect underground. Spirit middle men are probably involved. Korus spirits can also influence animal behavior. I have created a benign Mera spirit called “Fisherman’s Friends” that can summon fish towards fishermen that Mera is pleased with or repel fish from those Mera is displeased with. Mera probably has a few spirits that can create or move fresh water to those in need.