When Conquoring the Crystal Empire, he moved his tyranny to conquoring Equestria, becoming the most powerful unicorn in history. The immortal King Sombra ruled all by forced, feared by all, including the four pathetic princesses couldn't defeat him and his dark magic army. Mending every pony with a whim of his powers.

Until the King lost his spark after five hundred years of ruling and torturing ponies.
When a mysterious unicorn mare nearly succeeded on assassinating Sombra, he regain his spark and took an interest of her. When he tries and inslaving her….

To only realize his dark spells doesn't work on the temptress assassin.

(Cover art done by me :P)