Samurai Ghosts

The Samurai Ghosts were a small group of four undead, ancient warriors summoned to witness Jack's attempted seppuku.

History
These samurai ghosts were summoned by The Omen to witness Jack's seppuku.

The Omen referred them as "great warriors of past". They were clad in traditional samurai armor each with a mask concealing their face. When Jack defeated The Omen and refused to commit seppuku, they seemed displeased but respected Jack's decision. They then returned to their respective graves.

Trivia

 * It is possible that they were Jack's ancestors. One of Jack's negative personalities, Anguish told him that their ancestors waiting for both of them. Anguish also hinted seppuku during his argument with Jack.
 * The second spirit's kabuto helmet resembles the face of Aku with the eyes, mouth and rugged, long beard.
 * The helmet design also resembles the artwork of Jack in armor in the first promo for season 5.