Dark Kain

Dark Kain Highwind is a character from the world of Final Fantasy IV. He is the evil side of Kain Highwind, and represents all of Kain's anger and jealousy towards his friend Cecil Harvey.

Known as Kain?, it also appears in Final Fantasy IV: The After Years working for the Mysterious Maiden. Throughout the game he is thought to be Kain Highwind, but is in fact his evil side. After the real Kain failed his mission upon Mount Ordeals, this evil form was created, and it sided with the Mysterious Maiden. He is temporarily playable during the course of the game.

Final Fantasy IV
Dark Kain appears during Kain's trial in the Lunar Ruins, which takes place in an alternate version of Baron. There, a figure in a black cloak has attacked people with a lance in the night, and escapes authorities by leaping across rooftops. The only clue to the crime is a blood-soaked lance Kain finds in his room at the inn. After more crimes, the lance continues to be found in Kain's room, which coupled with the assailant's reported jumping abilities cause Kain to be arrested as the culprit. Kain eventually apprehends a guard as the perpetrator, but returns to his room to find the blood-soaked lance once again. Dark Kain contacts Kain telepathetically, and tells him it cannot end until Cecil is dead. Kain realizes that Cecil is in danger, and follows Cecil into the Serpent Road, where they are teleported to a mirrored chamber. Kain finds Cecil unconscious and Rosa tied up, when Dark Kain emerges from the mirrors and declares himself the embodiment of Kain's deep-seated dark desires, and the world of the trial is one he has created for himself. Dark Kain tempts Kain to use the blood-soaked lance to kill Cecil and claim Rosa. If the player accepts, Kain absorbs his dark side and kills Cecil, failing his trial. If the player refuses, Dark Kain grabs the lance and attacks Kain. They battle, and Dark Kain transforms into Lunar Bahamut, but Kain manages to defeat him. Departing from his trial, Kain returns to the real Cecil and is questioned about what happened in his trial, but Kain does not tell him.

Apparently, the events of the Lunar Ruins are not canonical, as in Kain's trial his dark side is killed, while in The After Years Dark Kain is very much alive.

Final Fantasy IV: The After Years
He first appears leading an attack on Fabul. He then has a battle with Yang and Ursula but still manages to retrieve the crystal. He is then shown in a flashback of Porom where he rescues her and a Black and White Mage from monsters. When they return to Mysidia, Kain leaves Porom and the Elder to defend the town while he returns to Baron. In truth, he was retrieving the crystal for the Mysterious Girl. Kain's evil side later appears leading an attack on Damcyan but is confronted by Ceodore and the others. Despite their efforts he still manages to retrieve the crystal and abducts Rosa.

Kain's evil side is later confronted by Ceodore and his party in Baron's castle where he and his light side, the real Kain, have a final showdown and is ultimately defeated. Afterwards, the real Kain turns into a Holy Dragoon, winning new powers and abilities.

Battle
Dark Kain is fought as a boss in Final Fantasy IV: The After Years, facing Kain in a final showdown in Baron Castle.

Dark Kain also has a battle sprite in Kain's trial in Final Fantasy IV, which appears during the beginning of their battle. However, he is not a true enemy and does not appear in the bestiary. He cannot be killed, unless he is struck by a tornado from the Abel's Lance. He can, however, take damage, and counters all forms of attack with a physical attack. After a few turns, he transforms into Lunar Bahamut.