'The Pure Ones'

Elfs.
The most beautiful and respected group of humanoids to exist. They are considered our angels..
The Pure Ones.
And when you turn into an elf, as they say, "magically", you become perfect.
Oh, how they are the complete opposite.
Their beauty tricks us, so does their kind words.
People don't magically become elfs.
They get bitten or scratched.
People who survive the battle between an elf, and were bitten or scratched, they become one themselves.
That's the worse thing of surviving.
They become humanity's worse enemy.