This story is a sequel to Oathbound

"Promise me you will save him from his own darkness."

The final charge from Storm Emblem continues to ring in Sky Streak's ears. Seeking an opportunity to restore his fallen comrade, Sky journeys to Ghost's home in Vanhoover. But what he finds there is a pony consumed by regret and bitterness, wrapped in the black thoughts of failure and animosity.

Sky is prepared to go to great lengths to redeem his former commander, but when all is said and done, he will learn that the price of redemption can be terrible indeed--more than he could have ever imagined.

This story is a sequel to Oathbound

After the events of “Oathbound,” the existence of the Alicorn Guard and the truth behind it was made known to all Canterlot, and gradually to all Equestria. In accordance with the wishes of the remaining members of the Guard, the Royal Council chose to disband the force and reorganize its remaining members into a more independent, organic-based corps designed to exist all across Equestria and defend it from all dangers as they arose. Some, placed under the command of Trucker, were assigned to remain within the bounds of the Solar Empire and took the name of “The Vigilant.” The others, under the supervision of Nighthawk, took to the task of seeking out threats beyond the borders of their homeland. Because of their constant travels, these ponies took unto themselves the title of “The Wayfarers.” But as much as they often acted independently of each other, they were still all members of that one group, forged from the ruins of the Alicorn Guard: The Sentinels of Harmony.
And thus, from the dying embers of one legend, another rose to take up the mantle as guardians of Equestria…

This story is a sequel to The Deepest Magic

The Chimera's defeat has heralded a new time of peace within Equestria. The future looks bright: the Crystal Empire has returned in the north, the devastation wrought by the Chimera has been almost entirely restored, and Twilight Sparkle has become Equestria's newest alicorn princess.
However, not all is perfect within the land. Princess Luna has fallen into a depression as she grapples with the errors of her past, and Sky Streak cannot shake the Chimera's final words about the source of hatred within the land, and the threat of its own return. But now that he is a member of the elite Alicorn Guard, he believes he is more prepared than ever to stand against whatever darkness rises against his home.
But as Sky prepares to once again face down the darkness, he will enter a dangerous game where nothing is as it seems. And when his world is shattered in one tragic moment, he will need to come to grips with his own anger and bitterness. Because if Friendship is the deepest magic, then the only way to conquer the darkness is to spread that friendship...even to your enemies.

This story is a sequel to Under the Black Sky

In the wake of the disastrous battle with the Chimera, Sky now rests in a coma within Canterlot Palace. The Council has become desperate to find a way to stop the monster's onslaught, but without Sky Streak, their options are growing thin. Twilight and the bearers of the Elements of Harmony prepare for an uncertain showdown with the Chimera, but with little knowledge of the Chimera's true abilities, their chances of success remain in doubt. But somewhere within Equestria, a lost spirit wanders in search of his identity. And when he finds it, he may discover the key to vanquishing the darkness has been with him all along.

This story is a sequel to Ice and Shadow

The sun still shines in Equestria, but for Sky Streak, he can't ignore the dark clouds on the horizon. Lurking in the shadows, he knows the Chimera is plotting not only his downfall, but all of Equestria's. And when the Chimera reveals itself to him in dreams, it pushes Sky to the brink. And when everything he knows is threatened, he must make a terrible choice: witness the fall of everything he loves, or challenge the darkness alone. But no matter his choice, there's no getting out of this one unscathed...if at all.

This story is a sequel to Roots of Fear

When the northern outpost of Polarmino is cut off from the rest of Equestria by an unnaturally vicious snowstorm, the Council sends Sky Streak to investigate. However, what he finds there will force him to confront an entire civilization of Equestria's most ancient foes. But even with a bag of tricks and a new ally, Sky may not be prepared for the greatest danger of all, which threatens not only his life, but the existence of all of Equestria.

The Everfree Forest has existed within Equestria for as long as anypony can remember. It was once the home of the Palace of the Pony Sisters, which was the seat of power for the realm until the Fall of Luna and the Rebellion of Nightmare Moon. But a darkness has slowly begun to seep from the forest, and Celestia and Luna have taken note. Together with the newly married Cadance and Shining Armor, they choose a young recruit to the Royal Guard to investigate the forest and search for the source of the darkness. He is young and untested, but he has incredible potential...perhaps more than anypony could have imagined.