Ongyo-Ki

Ongyo-ki (オンギョウキ, Ongyouki) is one of the new demons to appear in the series with it's first appearance in Shin Megami Tensei III: Nocturne. Ongyo-ki is the strongest of the Oni demons boasting multiple resistances, a high level, and a varied moveset.

Appearances

 * Shin Megami Tensei III: Nocturne: Brute
 * Shin Megami Tensei: Strange Journey: Brute
 * Shin Megami Tensei IV
 * Persona 4: Hermit Arcana
 * Devil Survivor Overclocked: Touki
 * Shin Megami Tensei IMAGINE: Brute

Shin Megami Tensei III: Nocturne
Ongyo-Ki is the leader of the four Oni that were part of the Mantra demons' elite force. But they made a mistake which angered Thor and they were forever banished from Ikebukuro. The once elite Oni group became mere petty thieves who mugged anyone going through their scattered hideouts around the Ikebukuro Tunnel.

Ongyo-Ki's hideout is within the central area of the Ikebukuro Tunnel close to the ladder that leads to the station near Asakusa. However, he will not appear until his 3 subordinates have been defeated. If Hito-Shura manages to meet up with him, Ongyo-Ki will ask if he is the one who murdered the former's comrades. if Hito-Shura confirms this, Ongyo-Ki will challenge him to a duel.

Ongyo-Ki has a special ability to replicate himself. If any of the replicas are hit, he will retaliate with a powerful attack. The only way to see through the illusions is to battle him during a Full Kagutsuchi phase. With the light of Kagutsuchi reaching even in the darkest recesses of the tunnel, the real Ongyo-Ki's shadow can be seen on the surface, negating his tricks and making him vulnerable.

Persona 4
Ongyo-ki can only be obtained by maxing out the Hermit Social Link and performing a Cross-Spread fusion consisting of the Oni, Fuu-Ki, Kin-Ki and Sui-Ki Personae.

Shin Megami Tensei: Strange Journey
Ongyo-ki is a special fusion, created by fusing together Fuu-Ki, Kin-Ki and Sui-Ki.