Bestiary
Here are the definitions for each creature mentioned in the prophecy. Some of it is from Harry Potter Wiki, and some I came up with myself.
The berserk is a bear warrior, who was said to have fought in a trance-like fury (berserker), another meaning is furiously violent or out of control. Because of this, they are prone to succumb to insanity, having trouble fighting their own mind. They need a robust support system, a family, a pack to prevent it. They can't be forced into a loveless marriage or sustain the loss of someone they're attached to. Due to this, berserks without the pack prefer to spend their lives alone to avoid additional deterioration of their already fragile mind.
The vampire is a creature known for biting people on the neck and sucking their blood. Since scientists created ways to preserve blood for future transfusions, modern-day vampires do not need to feed specifically from a living person. Vampires can manipulate others' emotions – the ability once used to appease their victims to avoid resistance. This ability allows them to form an emotional bond with their family members or other person/creature of choice. But if this skill is undeveloped, it can turn against a vampire, emotionally overwhelming them, causing constant excruciating headaches, nausea, fatigue, or even mental insanity.
The veela is a beautiful woman with white-gold hair and moon-bright skin. They can hypnotize people with their immense beauty. Once a human being is put into this trance-like condition, veela can enter this person's mind, cutting past all mind shields like a hot knife through butter. Often, they cannot control their charms, making it hard for them to differentiate the true intentions behind someone's actions. With such a substantial prejudice toward veela and other dark creatures, their ability to enter other people's minds, even though it seems invasive, is a matter of survival. Blood relatives or those who formed blood bonds with veela are the only ones, except for people who are not attracted to women, who cannot be influenced by their charms, or whose thoughts they're unable to read.
The phoenix is a large swan-sized scarlet magical bird with red and gold plumage, a golden beak and talons, black eyes, and a tail as long as a peacock's. They are one of the most independent and detached creatures in the world. For them to create a bond with someone is not a necessity but a privilege. Since phoenixes are one of the most loyal creatures ever known, they can arrive to the aid of those they're devoted to. Phoenixes are immune to the gaze of a basilisk and stay unaffected by hellhound's flames. Their tears have potent healing capabilities, being able to bring a person back from the brink of death.
The hellhound is a hound that embodies a guardian of Death herself. They are commonly black, anomalously overgrown, supernaturally strong, and often have red eyes or are accompanied by flames. Hellhounds are incredibly loyal to those they deem worthy, following their loved ones through life and death. Their flames are said to be hotter than a sun, making them immune to basilisk's venom, instantly burning it from their bloodstream, while red eyes allow hellhounds to sustain the killing gaze. Since hellhounds and dementors are the creatures of the Death, the former being her guardians and the latter being her servants, it's impossible to consume a hellhound's soul through the dementor's kiss.
The basilisk is a giant serpent known as the King of Serpents. Looking them directly in the eyes caused instant death, but an indirect look would merely render the victim petrified. Basilisks usually have dark green scales and a lighter green underbelly, and their skin is armored like a dragon's, deflecting spells cast upon it. They also possessed rows of incredibly sharp poisonous fangs and large yellow eyes. The basilisk's venom can kill a person within minutes, making the person drowsy and blurring their vision before death, and the only known antidote is phoenix tears. They cannot be forced into a magical bond since the power imbalance drives basilisks to insanity, awakening extreme murderous tendencies they cannot control.