The King of Fighters '99: Millennium Battle (1999). Play online

Summary

The King of Fighters ’99 – also known as KOF ’99 – shook up the series by expanding every roster to four members, introducing a dedicated "Striker" who hops in, throws a special attack and disappears. Players still pick three fighters for the round, while the fourth waits on the sidelines and can be called in a limited number of times via the Strike Bomb counter. This new assist mechanic opened the door to deeper combos, a move the developers emphasized when they scrapped the dual‑style system of the previous title and returned to a single gauge‑based system modeled on the former Advanced mode.

The game also added two powered‑up states: Counter Mode, which boosts offense and lets you spam Super Specials, and Armor Mode, which fortifies defense at the cost of those Super moves. High‑scoring performances unlock a secret post‑boss showdown against series veterans Kyo Kusanagi or Iori Yagami. Critics praised the refreshed mechanics and the striking artwork by Shinkiro, noting that the Striker system gave longtime fans fresh strategic depth while staying approachable for newcomers.

Storyline

The King of Fighters '99: Millennium Battle picks up two years after the 1997 showdown. Kyo Kusanagi and Iori Yagami have vanished since they sealed the evil Orochi, and mysterious invitations summon fighters to a secret tournament hidden from the public eye. New teams appear: K' and Maxima join Benimaru Nikaido and Shingo Yabuki as the Hero Team, while Takuma Sakazaki returns to the Art of Fighting squad and Mai Shiranui finally becomes an official Fatal Fury member. The Female Fighters Team features King, Kasumi Todoh, Blue Mary and newcomer Li Xiangfei, and the Ikari, Psycho Soldier and Korea Justice teams each gain a fresh recruit.
The hidden organizer is the NESTS syndicate, led by the clone‑master Krizalid. He deploys data‑driven Kyo clones and fights in two forms, shedding a data‑analysis coat to become stronger. After Krizalid’s defeat, a NESTS superior kills him, and the remaining agents assault K' and Maxima, who reveal themselves as former NESTS test subjects. The duo survives, escaping the collapsing arena as the secret tournament ends.