Spike had been captured by a alien group called the Kraang for some time now, he was taken away after he just wanted to have some time to reflect. He was taken away from Equestria and brought to another dimension, he was in captivity for some time, but he then meets two strange creatures called" Human's" and are thrown into his cell, he meets a girl called April who has caught they're interest as well.

After some time waiting they are rescued by a group of 4 mutant turtles, after they fail to rescue April's father, Spike is now freed but without anywhere to go, so the turtles take Spike in and is trained by Master Splinter to stop the Kraang and return home.

New Cover art is thanks to Dragonknife 5, he helped make this and all credit goes to him.

Unhappy that her future as a member of the monarchy is denied by Celestia, Sunset Shimmer escapes through Starswirl's mirror into another world, planning to take it over to prove once and for all she was fit to rule. What she didn't expect—besides a species change—was to arrive in a world already conquered.

TvTropes Page (Just created! Needs Help!)

Art (Will contain spoilers)

Sunset Shimmer - Bloody Sunset

Spoilers Ch. 11+: Angel - Angel and Sunny
Spoilers Ch. 18+: Princess - Comic
Spoilers Ch. 121+: Alejandra Acevedo - Flying at the speed of death
Spoilers Ch. 161+: Apple Bloom - Bloom
Spoilers Ch. 180+: Food - Sunset's Party Dress
Spoilers Ch. 185+: Fugue - Fugue by Rametep
Spoilers Ch. 197+: Exhausted

(Art is always welcome!)

WARNING: CONTAINS SPOILERS FOR THE WHOLE STORY: TIMELINE

This story is a sequel to Rider on the Storm

For the briefest of moments, Anonymous wielded absolute power. He single-handedly destroyed the city of Canterlot, laid waste to Ponyville, decimated the Everfree Forest, and came dangerously close to annihilating the very Tree of Harmony itself. And he had an absolutely fantastic time doing it.
Right up until he lost.
Now he's stuck as a statue under the watch of the princesses he tried to subjugate, awaiting the time he'll be locked away forever, with the key no doubt thrown into a volcano. But from the very beginning, Anonymous suspected that the shenanigans of the good guys would cost him his victory at the last moment, and so he laid plans with his most loyal of subjects—all former soldiers of the Storm King he betrayed to obtain his power—to arrange for his release should the opportunity arise.
Unfortunately, he wasn't counting on the ponies calling in help from a faraway land. Enter the Four Princes of Zebrica, all wielding the same exact power that Anonymous did, and knowing a thing or two about how to put bad apples like him away for good. This is made even worse by the sorry state of Anonymous's storm beast forces, having hit hard times in the months since his defeat.
But not all is lost for the petrified supervillain. Because in a rare twist of luck, the Princes just so happen to unknowingly bring with them a zebra criminal with his own dirty little secret. A secret that not only secures Anonymous's release from captivity, but just might be the start of a horrifying new partnership, and with it, the birth of a new force of evil.
And of course, with all that going on, there's always the matter of the nascent Legion of Doom, plotting to bring their own age of darkness to Equestria as well...

Takes place during the final two seasons of Friendship Is Magic. With a few alterations here and there, because I HATE THE ANTI-FIM I HATE THE ANTI-FIM :bread:
Reading Rider on the Storm is strongly advised if you want any idea of what the hell is happening in this story.