Cassandra Clare

Witches and warlocks can only use magic because they have demon blood.”

“I use tools that are magical. And just to be able to do that, I have to undergo rigorous training. The rune tattoos on my skin protect me too. If you tried to use one of the seraph blades, for instance, it’d probably burn your skin, maybe kill you.”

If you were half as funny as you thought you were, my boy, you’d be twice as funny as you are.”

If you were half as funny as you thought you were, my boy, you’d be twice as funny as you are.”

If you were half as funny as you thought you were, my boy, you’d be twice as funny as you are.”

Because they’re half-human, half-demon. All witches and warlocks are crossbreeds. And because they’re crossbreeds, they can’t have children. They’re sterile

All Downworlders are in some part demon, but only warlocks are the children of demon parents. It’s why their powers are the strongest.

Vampires and werewolves are the result of diseases brought by demons from their home dimensions. Most demon diseases are deadly to humans, but in these cases they worked strange changes on the infected, without actually killing them. And faeries—”

Faeries are fallen angels,” said Dorothea, “cast down out of heaven for their pride.”

It’s also said that they’re the offspring of demons and angels, which always seemed more likely to me. Good and evil, mixing together. Faeries are as beautiful as angels are supposed to be, but they have a lot of mischief and cruelty in them. And you’ll notice most of them avoid midday sunlight