Leona Heidern is the adopted daughter of Heidern and a member of the Ikkari Warriors Team. Leona is a descendant of Orochi.
King of Fighters: Another Day
Episode 3: In the Dark
Ikkari Warriors Ralf, Clark and Leona are dispacted to deal with hackers that have broken into their computer systems. The hackers are looking for information on the Kyo clones and a missing scientist. The group comes face to face with K' and Maxima and a fight breaks out. Clark takes on the large cyborg while Leona and Ralf face off with K'. Ikkari Warriors Clark manages to trap Maxima in an arm lock but Maxima deploys his arm launchers and blows the doors off the subway car the group is on. Maxima grabs K' and they manage to escape.
Episode 4: All Over
The Ikkari Warriors make a cameo in the final episode to determine if Kyo Kusanagi is the original or a Clone. Kyo lights up his flame and inquires if any of them are willing to find out.
Leona was raised by Heidern after he found the amnesic young woman on one of his missions. He trained her in his fighting style (thus they have a similar move set).
Leona is a descendant of Orochi and is susceptible to the Riot of Blood which turns Leona into a virtually mindless killing machine. Her strength and speed levels go up exponentially and her intellect goes down. She is responsible for the death of her family and village.