Phoenix

If one tried to ask inhabitants of all the different worlds what the most annoying creature is, they would all answer the same way. Because nothing, no horror in this life or any of the afterlives could ever come close to trying to spend a few minutes with a phoenix. People would rather go through torture or a second Great Fae War than interact with them.

Appearance

The only good thing about the phoenixes is their appearance. They have a beautiful fiery, in some places metallic, plume that tends to change colors to always stand out from any background whenever they stay somewhere for a long time. They are about 1 meter tall when standing on their legs, from the ground to the top of their heads, and they are about 3 meters long when counting from the tip of their beaks to the ends of the longest feathers of their tails. They have a wingspan of 3 meters.
Phoenixes have heads similar in shape to those of hawks, though topped with feathers that take on shape of a crown. Following the head, there's a long, slender neck adorned with shorter feathers shaped like a mane made out of scales. When it comes to their torso, they tend to have really fuzzy, lighter feathers on their chests that take the shape of hearts, while at their sides and their wings, the feathers have patterns of dark circles. Their wings are similar in structure to those of peacocks. Their legs are muscular, but with shorter claws than one could expect. Lastly, they have long tails that look like waterfalls, with many layers that curl upwards.

Personality

Phoenixes are extremely arrogant and narcissistic. They consider themselves gifts of gods to all the worlds, good-luck charms, and the most beautiful, intelligent creatures that ever existed. They seem to love to complain about anything and everything and they will find flaws in anything but themselves. Should anyone point out any flaw of theirs, they will debate with them on that topic for the next few hours (at best), something there is no escape from. Each one of them tends to create their own rules about how they should be treated and how others should behave in their presence. A list that at best consists of hundreds of thousands of points. Should someone break any of said rules, even without knowing them, phoenixes will immediately inform them of their transgression and will keep reminding them of it for the next few years. After all, they are always right.
Phoenixes talk for hours, as if they love the sound of their own voices, sharing the stories of their adventures, romances, heroic might, diplomacy, and anything else that shows them as genius chivalrous nobles and saviors of the world loved by everyone. All of those stories are obviously fake, as most phoenixes don't leave the area they live in, lazing around until they find a potential listener.
They have a bizarre sense of humor that is embarrassing to anyone but them, and the most annoying laugh one could only imagine in their most insane nightmares.
They consider all other beings as lesser than them and tend to be really racist, and many other -ists. They just keep saying insensitive things aimed at anyone they can. When confronted about that, they will "kindly" explain that they cannot be since they speak the truth.

Abilities and properties

Speech and telekinesis

Had any god, deity, or demon given them the ability not only to speak all existing languages as well as project their thoughts to all the living beings in the area of 300 meters, they must have hated all the living beings from the bottom of their soul. Phoenixes can talk, and they use every single second of their lives to assure other creatures that they can do that. And when they don't talk, they sing. Or at least that's what they call the sounds the demons from all kinds of hells would consider too cruel to torture the souls with that come out of their throats.

Not really immortal

Phoenixes live only 30 years and technically can be killed. However, since they are so annoying, no afterlife wants them and so they keep sending them back to the world of mortals. Every time they die or get killed, they create a large explosion of fire hot enough to burn most of the things and cover everything in an even larger area with ash. There were occurrences where some of them kept dying in particularly stupid ways in the same area and just kept destroying more and more of the surroundings. When a phoenix gets sent back to the living, its body returns to the state it was just after it hatched, so the afterlife doesn't have to deal with it for as long as possible.

Imprinting

Woe to anyone who gets too close to the area just after the phoenix was reborn. If one of them notices anyone during the first few minutes since that happening, it will almost always imprint on them. From now on, for the next 30 years of their life (or hopefully shorter), it will follow the one they imprinted on wherever they go. This will doom them not only to 30 years of close proximity to the most annoying creature in all existence but also to a most certain life of exile for that period of time. Because despite their bad condition and slow speed of flying, once they imprint on someone, they will always know where to find them. So it will take them only a matter of time before their next reunion.

Fire-resistant

Since every time they get reborn, phoenixes create a fiery explosion that tends to set everything in the area ablaze, they are also completely resistant to fire. It is unknown whether said resistance is natural to them or did some kind of poor fire spirit encountered them in the past and had just enough of them that they made their whole species completely immune to high temperatures with their blessing.

Assured annoyance

It seems that even all of the universes can't get rid of those birds. Any spells that would simply annihilate them or destroy them out of all existence don't work at all on phoenixes. Even the Fae failed when they tried to untangle all of the concepts related to them and had to give up because the task was just not worth it. The phoenixes are just too annoying to be forgotten.
Additionally, if there is even the smallest chance a living being can encounter a phoenix or discover how truly annoying they are, fate seems to forcefully direct itself to ensure that happening, at least once in one's lifetime. There is no safety. It's also the reason why a technology that could ensure complete communication between the two different worlds hasn't been invented yet, because if there was a phoenix on one of them, both of those worlds would have to suffer being aware of them.

Uses, materials, and products

Materials, especially feathers, acquired from phoenixes are extremely valuable and have many useful properties. For example, creams and ointments made with the addition of their ground feathers might keep the patient in bad condition alive for longer, as death will mistake them for a phoenix and will delay coming for them for as long as the product lasts. Their feathers also make beautiful and surprisingly durable Stylish Quills as well as are used in the creation of fire-resistant clothes. But there is a reason why materials from them are so rarely gathered. Any material coming from a phoenix must be given by it willingly while it is still alive. And that means one has to deal with them for long enough that they start to trust them and share said materials. There aren't many gatherers in all of the worlds who are willing to subject themselves to that torture, no matter the price.

Lifespan

30 years, but not really, thanks to their "rebirths"

Flying speed

10km/h

Distribution

Their original world is unknown but ever since the portal to it has opened, they spread like a plague, "curious" of other lands.

Average Intelligence

Phoenixes don't know much besides themselves but that won't stop them from making things up and saying complete hogwash with utter confidence. Woe to someone who, not knowing of their nature and stupidity, turns towards them for help and will be too naive to notice they shouldn't trust anything they say.

Average Physique

Despite the appearance that would suggest that they are quite healthy, majestic, and athletic, phoenixes prefer to laze about most of the days, not doing anything. As a result, most of them are very poor at flying, both when it comes to speed and maneuverability. Just after a quarter of a minute of flying, they need rest and will breathe and cough heavily, having trouble catching their breath. They are also extremely clumsy, having problems with keeping their balance.

Social structure

Luckily, or unluckily to everyone, phoenixes tend to be solitary creatures that keep away from each other's territories. While there is a possibility that if they lived in flocks, they would all just group up together, leaving bigger parts of all the worlds safe from their presence, one could only imagine how quickly one's mind could break should they encounter more than one of them at the same time. But until today, it is still unknown how the two of them would interact with each other should they meet. Would they be positive to each other, hostile, would they finally understand how painful it is to deal with one of them, or would they love it? Would they see another phoenix as a reflection of their own beauty and grace? No matter the answer, many agree that they would never get to know it as all of the worlds might come out worse on that possibility.
Phoenixes don't mate, their number staying the same since the oldest texts that mention them, they don't lay eggs or have any offspring. Thanks to that, it is easier to monitor and avoid them.