Heidern/Story

Past
A 34 year old operative named 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 called the Ikari Warriors. Heidern would spend nearly a decade filled with hatred and rage against Rugal.

At one point, he found a little girl named 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.

The King of Fighters '94
Sometime before the 1994 tournament, Heidern receives a letter for the KOF tournament. He wants to enter the tournament to get his chance at revenge against Rugal, and entrusts entering with his two top operatives; Ralf Jones & Clark Still. They decide to enter KOF as the Ikari Warriors Team, representing Brazil.

The King of Fighters '95
Heidern, after several months of nightmares, is unconvinced that Rugal is truly dead. When Ralf & Clark show him the invitation to the 1995 tournament, they immediately went to enroll, forming again the Ikari Warriors Team.

The King of Fighters '96


Heidern informs Ralf and Clark that he will not be joining KOF anymore, as his long life goal of killing Rugal has been achieved, and he must oversee their mission to watch out for any suspicious activity for the tournament. To fill in the missing team member, Heidern enlists a new operative named Leona, who after a not-so-friendly introduction, forms the new Ikari Warriors Team.

The King of Fighters '97
Leona, for the past year, has been suffering from mysterious headaches and hallucinations. During a failed mission, Ralf asks Heidern to suspend them from active duty. In actuality, this was done for the three to form the Ikari Warriors Team to investigate what's happening with Leona, believing this to be related to Goenitz.

The King of Fighters '99
Sometime before the 1999 tournament, Heidern informs Ralf, Clark, and Leona that they'll be entering the 1999 tournament with a fourth member, as this year's tournament now has Teams of 4 instead of 3. Heidern is unable to join due to him dealing with espionage operations at that time, so make up the fourth member, Heidern promotes Whip as a member of the Ikari Squad.

Throughout the tournament, Heidern had been observing the tournament, keeping a watchful eye out for anything suspicious, when he gains a report that Kyo Kusanagi, the man who went missing after defeating Orochi, was alive. However, to his shock, discovered that hundreds of people bearing Kyo's face had appeared in various locations around the globe, with two appearing in the tournament.

A few hours after the tournament's conclusion, Heidern and his group found Krizalid's corpse and brought it back to their base, however it would soon be taken by Zero not long after.

The King of Fighters 2000
Nearly a year after the events of the 1999 tournament, Heidern is determined to figure out the objective of the NESTS cartel so that he can stop them from achieving their ruthless ambition. A fellow commander and long-time friend of Heidern, named Ling, tells the Heidern that K' and Maxima (two fighters who were present at the last tournament) may hold the key to locating the whereabouts of the mysterious organization. Using this information, Heidern decides to focus his efforts on finding the duo so that they can be captured and interrogated for information.

At one point, his own group was infiltrated by one agent of NESTS who stole the identity of one of his allies and attempted to sabotage their operations. Heidern killed him once he saw an opening.

The King of Fighters 2001
He participates in The King of Fighters 2001 tournament alongside Ralf, Clark and Leona. They advance through the tournament, but is defeated by the Hero Team with Heidern losing to the leader. Heidern reveals that his reason for entering wasn't to win, instead it was to locate the leader of NESTS using the KOF tournament as a distraction. In the team’s ending, Heidern announces to his group that the NESTS case is closed.

The King of Fighters 2003
Months before The King of Fighters 2003 tournament, Heidern sent his men to investigate the flying vessel known as Sky-Noah. 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.

The King of Fighters XI
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.

The King of Fighters XIII
Heidern orders the team to investigate whatever role Those from the Past and Rose Bernstein have in the KoF XIII tournament. He also updates Seth, Vanessa, Ramón and Blue Mary on the current situation and tells the agents to disembark on the navel port so they could infiltrate the stadium and find out what Ash and the clan are planning. He puts Seth in charge of the matters on the side.

The King of Fighters XIV
Heidern hands the invitation to the Ikari Team and confirms that he's already done a background check on the tournaments host. He informs the team on the recent reports regarding the distortions in spacetime, along with NESTS activity increasing during the same time period. He tells them to infiltrate as usual.

After receiving the information Maxima provided Heidern dubs the entity as Verse, he tells everyone in the room to continue their investigation. 36 hours after the tournaments conclusion, Heidern confirms that there are bodies that were resurrected and has already commenced a 24 hour surveillance. After the meeting he tells Leona that Gaidel's resurrection has not been confirmed, Leona responds that she's not concerned.