[Sedaiyus]

With some exceptions or rare circumstances, the removal of vital organs, decapitation, blood loss, severe damage to vital organs, and suffocation for those who need oxygen will kill just about anything across the board.

Werewolves Weakness
Wolfsbane- this plant is toxic to werewolves. In extreme cases it can poison them leading to death but in most cases it severely weakens them and has physical symptoms similar to food poisoning.

Silver- werewolves are allergic to silver though older werewolves can build a tolerance to it. If the silver damages their heart it can kill them. It causes intense burning pain to those without a tolerance and can be crippling.

Moon Phases- werewolves until they reach phase 3 are subject to being manipulated mood wise by the phases of the moon and whether or not they lose their intelligence during transformation.

Vampire Weakness

Vervain- ingestion of vervain causes a vampire to become severely feverish and weak to the point that it can even hinder their healing abilities as well. The effects can last 10 minutes to 10 hours depending on the age of the vampire. Just touching the plant is not enough to do harm to a vampire however. When mortals ingest vervain it prevents vampire from effecting them with their compulsionary abilities.

Sunlight- vampires cannot naturally walk about in the sunlight. Direct sunlight will burn them, set them ablaze, and they will burn to ashes being highly flammable. Indirect sunlight will weaken vampires.

Fae
The Fair Folk- Faeries are often referred to as ‘the fair folk’. It may surprise you just how true this is. Every fae, regardless of affiliation, is incapable of breaking a deal. If a bargain is made with a fae, they must hold up their end of it, with no exceptions. This includes bets! Fae love to gamble, and it’s great fun to take a chance, but they are incapable of welshing out, unless they can find a loophole.

Iron- Like silver to werewolves and sunlight to vampire, iron effect Fae the same way. Burns them and if ingested is poisonous. Being around iron for too long will weaken them and make them sick too.

Demons
Holy objects or forces- Anything from holy fire and smiting to holy water and holy symbols hinder, hold, harm, or kill demons.

Angels
If an angel dies in a corporeal form in a host, they will be permanently killed.

[Sedaiyus]

Hierarchy of Powers
The lower the tier, the more powerful the entity or being is. Everyone in the same tier is relatively of equal power. This accounts for overall power and lethality too not specialized traits. It is likely a Demi-God in Tier 6 can be physically stronger, strength wise, than a Fae in Tier 6, but that Fae has something to even the playing field in another area, making their overall power equal. Essentially this is how it stands currently:

Tier 1: Primordial Gods, ArchAngels, 2 Demon Princes

Tier 2: Titans, Apophis, Gigantes, 4 Demon Princes

Tier 3: Major Pantheon Gods, Seraph, ArchDemons

Tier 4: Minor Gods, Higher Angels, Greater Demons, Fae Leaders, Primordial Vampire

Tier 5: Demi-gods of Major Pantheon Gods or Titans, Angels, Higher Demons, Fae Elite, Alpha Werewolves, Ancient Vampire, Best Mystics, older or strong bloodlined Cambion and Nephilim.

Tier 6: Demi-gods, Demons, Fae, Veteran Werewolves, Elder vampire, Veteran Mystics, Cambion, Nephilim, Most Monsters

Tier 7: Mystics, Werewolves, Upper Vampyre-Ascendant Vampire, 2nd Generation Demi-gods, Shadowhunter Nephilim, Enhanced Human Hunters

Tier 8: Novice Mystics, Young Werewolves, Fledglings-Lower Vampyre, Weakest Fae, Spirits

Tier 9: Humans

There are always exceptions and special circumstances but this is generally how it goes. That doesn't mean an exceptionally powerful Demi-god of Odin or Zeus or a Priestess of Ra Mystic couldn't take on a minor god or greater demon and win but this would be victory in the battle, forcing a retreat, banishing, surviving ect. They wouldn't be able under most cases be able to kill or destroy anyone in that tier above them. This is also a measurement of raw power and doesn't factor in experience, skill, special items, numbers, tactics ect that might supplement the difference. Hopefully this gives at least an idea where everything stands in correlation to each other.