A long time ago. Final fantasy III came out with a new approach to learing magic. The characters would be equipped with espers(magical beings) and as they fought more battles, they would learn spells from the espers. What if a similar approach to learning magic was applied to a P&P rpg?
The players encounter an organization dedicated to toppling tyrannous governments; both good and evil. Secretly, they are led by the twin daughters of Lucifer / The Lightbringer / (Generic Adversary God). These daughters have an appropriate set of divine or demonic powers, but strictly speaking, are not evil.