Kusanagi is an anti-hero in The King of Fighters video game series.
He is a Kyo Kusanagi's clone who is created by NESTS. He shared an ending with two other Kyo clones, depicting clones that awakened in the destroyed NESTS facility.
In KOF 2003, reveals that he is a miraculous product of Chizuru Kagura, used to test the strength of tournament players. His evil appearance may be because he was created by Chizuru under the control of Mukai (the leader of KOF 2003 operation) and Botan (the puppeteer controlling Chizuru). Since he did not appear in the sequel KOF XI, the place of Kusanagi was not known after the events of 2003.
However, he is dispatched by Chizuru to any intruder (such as a player) to guard an area. Players must fight through Kusanagi to enter the next level. He used his mobile device in his previous game to launch a projectile or, in some cases, to fire a red flame (even if he summoned his own white silhouette copy to throw a projectile). His terminator is Orochinagi, which can send a whole set of projectiles that can kill the player's character almost instantly.
Similar to Kyo-1, he's serious at most times. Kusanagi has special quotes against characters just like Kyo, Iori, K', and K9999 in KOF 2002. Its possible that since he does not have the same voice as Kyo (until KOF Sky Stage, which he was voiced by Kyo's voice actor), they gave him the voice of Mitsuo Iwata to make him significantly different from his fellow clones as a unique doppelganger to Kyo.