Blade Maidens

The hero, Lux, has received an order from the King.
Together with the Blade Maiden sisters Honoka and Himeka, he must defeat the Demon King.
After a desperate fight, they finally had her cornered.
However, as she was on the verge of death, the Demon King unleashed a powerful magic, turning Lux into a gem.

To save Lux, Honoka and Himeka flee to recover the energy needed to defeat the Demon King once and for all, but...