Corrin

"Like Mark in Fire Emblem, Kris in Fire Emblem: New Mystery of the Emblem: Heroes of Light and Shadow, and Robin in Fire Emblem Awakening, Corrin is the customizable avatar character in Fire Emblem Fates. Unlike the others, however, they are also the main character of the story, having the most prominent role of an avatar character in a Fire Emblem game. Corrin's gender, physical appearance, voice, stat builds, and secondary class can be selected by the player before playing. Corrin is notably half-dragon, being able to transform parts of their body into that of a dragon, or temporarily transform into a dragon with the power of Dragonstones. Corrin and their royal families can use Dragon Vein, a power granted from the ancestral First Dragons, which can be used to alter the user's surrounding terrain in a multitude of ways.

Fire Emblem Fates centers around two kingdoms: the militant kingdom of Nohr, which is where Corrin grew up after being , and the peaceful kingdom of Hoshido, where Corrin was born. In the beginning of the story, Corrin becomes of age after they best their older brother, Xander, in a practice match. King Garon of Nohr provides Corrin with the sword Ganglari to be used on the Hoshidan prisoners Kaze and Rinkah, among others. Corrin succeeds in defeating the prisoners, but refuses to kill them, due to their kind personality. Enraged, Garon has Xander kill the prisoners instead, but Corrin refuses to allow it and briefly clashes with Xander, only for the argument to end when Leo "dispatches" the prisoners, secretly weakening them enough not to be killed and convinces Garon to lessen Corrin's punishment.

Garon decides to send Corrin to inspect a Hoshidan fortress above the Bottomless Canyon to pardon their crime. However, one of Garon's men, Hans, provokes the Hoshidans into battle and knocks Gunter, one of Corrin's companions, into the abyss of the canyon. Hoshidan soldiers soon find and capture Corrin, who eventually recognize them as the long-lost member of the Hoshidan royal family. Corrin then meets their blood relatives and the songstress Azura, a former Nohrian Princess raised in Hoshido, at the capital city. However, a hooded assassin attempts to kill Corrin, with Corrin's mother, Queen Mikoto, shielding them at the cost of her life. Distraught at her , Corrin transforms into their dragon form for the first time and goes on a rampage. During this time, invisible soldiers continue to attack Hoshido; they and the hooded assassin are driven back by Corrin and their allies. Corrin continues their rampage, but is calmed down by Azura, who sings Lost in Thoughts All Alone to revert them to their human form. In the aftermath, Corrin comes to possess the legendary Yato blade, which is said to belong to the one who will save the world. Corrin's families eventually meet together in battle, and Corrin is to side with either their adoptive family in Nohr, or their blood family in Hoshido, or choose neither side and fight them both. After the battle, the story continues with Corrin returning to their chosen family, or if they chose neither side, dropping into the Bottomless Canyon with Azura.

Corrin's starts in the Nohr Prince/Nohr Princess class, a class exclusive to them and their child, Kana. In this class, they can wield swords and Dragonstones. They can also draconically transform parts of their body to attack when attacking using Dragon Fang skill. With a Master Seal, Corrin can promote to a Nohr Noble and gain the ability to wield tomes, or to a Hoshido Noble and gain the ability to use staves. In addition to this, Corrin has a wealth of other options - they can reclass into their secondary class with a Heart Seal, their spouse's base class with a Partner Seal, or an A+ supporting character's base class with a Friendship Seal. As they are able to Support almost nearly every playable character in the game, this gives them a myriad of possibilities for reclassing. Finally, they can use any of the various special reclassing items to access otherwise inaccessible classes, such as the Dread Fighter, Ballistican, or even character-specific classes like Marth's Lodestar class."

via SmashWiki