Creation of Fiends

Life, Birth

Lucifer created the Fiends

Because the prime deities were no longer on the prime plane, they gave mortals access to arcane magic, as well as there own divine magic. Lucifer took this chance to create his own life, to combat the good in the world with his Fiends. As that's how most saw him now, he took it to heart and became the King of the Fiends.