Alternate universe where the Crystal Heart didn't kill Sombra and is instead used for his own dark purposes

Princess Celestia had always protected Equestria at any cost, even if she had to fight her own sister. Can Princess Luna do the same?

When Twilight Sparkle succumbs to King Sombra's dark magic, will her friends be able to save her in time before she loses herself to the darkness forever?

What if King Sombra's magic had a lasting effect on Twilight?

Things seem to be over, but something dark still lurks in the back of Twilight's mind. Will she be able to overcome it, or will it take hold of her and turn her to a life of corruption?

Twilight has done things she regrets. Things that she wishes she could take back. But nothing she can do will ever fix the past. And when the forces of Darkness at work again, she fears she may only have more regrets.

Corruption has led to Equestria becoming a wasteland, when the Princess of Friendship gives in to a former King. Will Equestria ever recover?

Spike never went down the stairway to save Twilight from Sombra's door. This is what happened after.

After Twilight's Possession the monster that possess her unleashes darkness all over Equestria, summoning the supernaturals and reanimating the dead. As Equestrian grow infested by this darkness, the Mane 6 are now no more. How will anyone deal

Twilight Sparkle and her friends must protect Crystal Empire from King Sombra and King Umbreon! But will she triumph or be corrupted by Dark Magic?

King sombra is back but not just for the Crystal Empire.........

Sombra is back! This time, Equestria will never be the same. Shortly after her coronation, Twilight Sparkle is teleported beneath the caves of Canterlot. In these caves, she will discover secrets bet left untouched.

In this dark future of Equestria, the CMC have become the guardians of the remaining ponies against the chaos demons, Nightmare Luna, and the crystal ponies of the formless King Sombra. Three deities, but an unknown fourth comes for conquest

King Sombra decides to pay Twilight Sparkle a..... visit. He uses his magic impregnate her and Twilight gives birth to the foal.