Heidern

Heidern is a character from Ikari Warriors, Metal Slug and The King of Fighters Series, he makes his debut on Ikari III: The Rescue appearing in the NES version of the intro and his playable debut was in The King of Fighters '94 teaming up with Ralf Jones and Clark Still as part of the Ikari Team.

He is the adoptive father of Leona Heidern.

Story
Eight years prior to The King of Fighters '94 tournament, a 34 year old Heidern was just promoted to his current rank for his exceptional proficiency in martial arts and strategy. The event took place at a top-secret base in Brazil and his wife and daughter were present for the ceremony. Rugal Bernstein, who caught wind of Heidern's high marks, stormed the base when he was away and killed fifty secret service officers on his arrival. When Heidern hurried back from his duties, Rugal deprived him of his right eye and deemed him unfit to be a part of his collection. Instead, he murdered Heidern's wife and child. Disgraced and alone, he developed his own fighting style and mercenary unit, the Ikari Warriors. Since then, he pursued Rugal to avenge his loved ones' deaths.

Sometime before the King of Fighters tournaments, he found Leona as the last survivor of a destroyed village. The girl was amnesiac and Heidern adopted her to care for her. He originally forbid her to partake in any training yet became lenient due to her inclinations on the matter. His refusal to give her a formal rank is his way of protecting her from some of the dangers on the battlefield.

Beginning in The King of Fighters '96, he assigns Leona to take his place in the tournaments while he issues orders from the sidelines. He continues to play a major part in one of the series's story arcs, the NESTS Saga, since the Ikari Warriors are trying to destroy the NESTS group. He continues this role with the incidents surrounding the mysterious group known as Those From the Past. When Leona experiences the Riot of the Blood after the 2003 tournament, he decides to pull her out of the following one and stay by her side while she recovers. After hearing Ralf and Clark's personal assessment of Leona, he lets his adopted daughter enter the tournament once more. In the end of KOF XI, the Ikari Team managed to secure Magaki's corpse and intended to analyze it, but the cruise they were on got invaded by Shroom and Rimello. The duo took Magaki's corpse, and Shroom also stole Heidern's eye patch and began to wear it as an insult and proof of his ability. Heidern orders the team to investigate whatever role Those from the Past and Rose Bernstein have in the KoF XIII tournament.

Ikari Warriors/Metal Slug Appearances
Metal Slug 8 (Ratbrute)

He is one of the starter playable soldiers from the game.

Metal Slug 8 (TheProjectXZoneFan1997)

Heidern is one of the DLC soldiers of the game.

Metal Slug 12

Heidern returns as a P.o.W. Helper on Final Mission.

Crossover Appearances
The King of Fighters XV (TheProjectXZoneFan1997)

He is part of the Master Team alongside Saisyu Kusanagi, Tung Fu Rue and Takuma Sakasaki.

Project X Zone 3: Sacred Destinies

Heidern appears as an NPC.

Capcom vs. SNK 3: Fight of the Millennium 2015

He is one of the playable characters of the game.

Capcom vs. SNK 3: Ultimate Tournament 2017

He is one of the newcomers.

The King of Super Smash Fighters

Heidern appears as a Striker for Ralf Jones.

Trivia

 * Heidern has also used the codename Bechstein in the past. Adelheid also gives him the nickname Heidi, which is a reference to the German novel character.