Saiki (斎祀 or サイキ) is the main antagonist and sub-boss of The King of Fighters XIII. His official nickname is The One who Rules Time (時間を統べるもの Toki wo Suberu Mono). Although his boss form is unplayable, his normal form is included as an unlockable character in the console versions.
He is voiced by Sōnosuke Nagashiro.
Saiki is the leader of Those from the Past, serving as the mysterious aforementioned "master" of said group from the "Tales of Ash" story arc's earlier installments. A being that has been described as the Western emissary of Gaia, he desires to gather life energy throughout the tournament to reawake Gaia's will and use the entity for his own means. To do so, he requires a particular ceremony to open a direct doorway to it. In the tournament finals, he appears to the winners to kill them, in order to gain the energy required to open the gate. When Mukai volunteers to deal with the winning team, Saiki isn't up to seeing his follower fail yet again and absorbs Mukai's energy into himself. With their combined strengths, Saiki faces the fighters, hoping to sacrifice them.
After the fight, Saiki remarks that they are doing well, though not good enough to satisfy him. He then suddenly notices that, instead of opening, the Gate was closing. Before he can suspect his followers of betraying him in some manner, Ash uses this moment of weakness to rob Saiki of his spirit. But, contrary to Ash's plan, Saiki finds him to be a suitable new host, manipulating the youth's body as his own and desiring to complete the job by fighting the winning team once again. He is defeated, however, and as Ash manages to retake control over his body after the battle, Saiki orders him to cross the gate so they can retry again. Ash refuses to restart time with Saiki, resulting in both being erased from existence.
Confident in his own strengths, Saiki believes himself to be a supreme entity of power. He talks in the same flamboyant manner as Ash, openly stating whatever lack of interest he feels. Saiki is rather malevolent and doesn't feel the slightest speck of remorse for the carnage he causes. He is very arrogant, and he takes pride in his "ascendant" status as an ancient entity and as such, has a "God complex" that is the primary source of his arrogant behavior, further reflected even in his fighting style. He often talks down on the fighters that face him, quipping sarcastic and rude dialogue towards his opponent (a trait that his modern descendant seems to have inherited) and often pointing out that he/she is a human, something Saiki considers as "worse than trash".
- Translocation - Saiki can translocate himself from one place to another.
- Dark Flames - Saiki can control dark flames, somewhat similar to the ones Evil Ash controls.
- Absorb powers - Saiki has the ability to absorb the powers from other people to increase his strength.
- Possession - Saiki has the ability to merge with and possess other individuals.
- Time Manipulation - Saiki is able to defy the flow of time at will, thus explaining the sudden appearance of Those From the Past.
- Shape/Size Shift - Saiki has the ability to transform from his "normal" state into a larger, more muscular form.
- Dark Energy Master - Saiki has the ability to control a special dark energy. He has displayed this ability only after absorbing Mukai's power (see Absorb Powers above), so it is unknown if this ability is inherent of him, or is absorption-dependant.
- Dark Energy Attacks - He can infuse his basic attacks (punches, kicks...) with dark energy for increased damage.
- Dark Energy Projectile - He can create waves of dark energy to attack distant enemies.
- Dark Paralysis - His projectiles can cover and paralyze opponents with darkness, leaving them open to Saiki's attacks.
- Toki Wo Suberu Mono (The One Who Rules Time) - The King of Fighters XIII (normal form theme)
- Fate - The King of Fighters XIII (Awakened Saiki, boss form theme)
- Fate ~Arranged~: The King of Fighters XIII (when the music is set to "Type B", console version only)
- The King of Fighters XIII - Sub-boss, DLC character (Human Form, as EX Saiki).
Saiki makes his move at the end of the tournament finals in KOF XIII, freezing time and appearing before the winning team. A large gate with time-bending powers appears in the distance, and he sends his underlings to gather more energy for the gate. Mukai wants to avenge the defeat that he suffered in KOF 2003, but Saiki instead kills him, absorbing his power and transforming into a large, muscular form.
As a boss, he focuses on immobilizing the opponent using his Tokoyami no Fune (Ship of Everlasting Darkness) at both long and close range, followed by either the Kyoryuu no Ori (Distant Dragon's Sediment) - a 4 hit grapple - or his Desperation Move Kasumi (Divine Flock), dealing a considerable amount of damage.
As a playable character, Saiki uses an acrobatic fighting style using kicks, projectiles and teleporting. Most of his Desperation Moves are stronger versions of the special moves of his Awakened Form. Tokoyami no Fune is now a very powerful projectile move similar to Ash Crimson's DM Thermidor; Kyoryuu no Ori drains the opponent life and Kasumi (as his Neo Max DM where he briefly turns into his boss form) turns into a screen filler.
All of his moves also have their particles in the Japanese script written with katakana instead of hiragana, and are also written as puns/plays on similar pre-existing terms (but some with different kanji).