Alicorns are immortal ponies who have both a horn and wings and the magic of all three kinds (Earth Ponies, Pegasi and Unicorns). Though exceptionally rare, any pony kind can become an Alicorn through accomplishing an impressive feat, usually in the realm of magic ability. Celestia, Luna, Opaline, and Flurry Heart are known to have been born as an Alicorns. Alicorns possess incredible magic that places them among some of the world's most powerful creatures. As Alicorns have been associated with royalty, they have been known to forge and lead kingdoms and empires. The only known land inhibited by naturally born Alicorns is the nation Skyros with notable individuals hailing from it being Celestia, Luna and Opaline.
Sunny Starscout[]
Though born an Earth Pony, Sunny possesses Alicorn Magic that was awakened by the reunification of the three Crystals. When summoned, the magic manifests as translucent wings and horn, giving Sunny the abilities of illumination, flight, levitation and other undiscovered powers. The origins of Sunny's Alicorn Magic are thus-far unknown.
Princess Celestia and Princess Luna[]
Born as Alicorns in the mythical kingdom of Skyros, the two sisters, Celestia and Luna, were chosen by the three pony tribes to govern as Equestria's first rulers to maintain the new found unity among them ushering in a era of peace and harmony under their millennium reign at their castle in Canterlot despite this peace faced various foes (including Discord, Lord Tirek and King Sombra and Luna as Nightmare Moon), eventually in their long rule, the Princesses passed on the torch to Twilight Sparkle, Celestia's former protégée and her friends retiring to a quiet life at Silver Shoals. It is unknown what their fate was after the rise of Opaline.
Princess Cadance[]
Twilight Sparkle[]
Long ago a unicorn named Twilight Sparkle became an Alicorn through completing an ancient spell due to her understanding of friendship. She would eventually go on to rule Equestria and used her powers to bring harmony to the land. At some point, she made the decision to gather and place all of the world's magic within three crystals known as the Unity Crystals to ensure that magic would only be used to bring the Ponies together rather than drive them apart. It's unknown as of now what became of her and her friends, though her home of Canterlot is known to now exist as deserted ruins.
Opaline Arcana[]
Not much is known about Opaline other than she appeared in Ponyville during the reign of Princess Twilight Sparkle. She embarked on a discrete but impactful campaign to instill distrust and resentment among the Earth Ponies, Pegasi and Unicorns to divide Equestria. At some point, she was temporarily defeated by Twilight and the Mane Six. However, her nefarious plans of dividing Equestria appear to have come to fruition, at least temporarily. By the time of magic's return and stabilization, Opaline is seen to occupy a dark, ornate castle. It is seen that she has the ability to observe distant events in detail through a magical projector, an ability seen among past Alicorns. She has at least one Unicorn servant, but likely has other personnel and assets at her command. Like other Alicorns, she has an immortal lifespan of more than a hundred years. She has a more clear understanding of magic, sensing that Sunny was able to reawaken and stabilize magic in Equestria. While her intentions are unknown at this point, they are clearly malicious in nature, and based around a possible conquest of Equestria. As of now, Opaline is the only known full Alicorn in modern day Equestria.