Master Xandred

Bio: Master Xandred, the Yokai leader, wields a broadsword and has the ability to seal his Yokai peers. He once fought the Shiba Clan's preceding Rangers and was sealed by the father of Jayden and Lauren, the prior Red Ranger, before his death. Due to the incomplete seal, Xandred is resurrected and resumes his mission to conquer the mortal realm. He terrorizes humans to cause the Sanzu river to overflow, aiming to flood the mortal realm and enable a full-scale invasion. His perpetual rage is only quelled by a specific medicine and the music of Dayu.

Dayu

Bio: Dayu serves as the trusted aide to Master Xandred, who shows her kindness only when she remains a dutiful and unquestioning servant. In her past life, she was Dahlia, newly wed to a man named Deker. On their wedding night, they exchanged gifts: a katana for Deker and a decorated guitar for Dahlia. Later that night, a fire engulfed their home. Dahlia awoke to flames, with Deker missing. They both escaped, but Deker sustained grave injuries. In desperation, Dahlia cried for help, and the "King of the Yokai" materialized. He promised to save Deker in exchange for Dahlia's humanity. She consented, but was deceived; both were transformed into Yokai, and Deker's memories were erased. After Deker's transformation, he disappeared, leaving Dahlia alone. Subsequently, she became Dayu, her Yokai form. Eventually, Master Xandred found Dayu, attracted by the melancholic tunes from her shamisen, which calmed his rage and headaches. He invited her to join him as a minion, an offer she accepted.

Octaroo

Bio: Octoroo is the strategist of the group, a cephalopod-headed spirit who awaited Master Xandred's revival. He regards humans as mere pawns for his experiments, seeking methods to overflow the Sanzu River. He also pilfered texts from the Shiba Clan, utilizing them to understand the seal on Master Xandred. However, he cautions Xandred against meddling with the Shiba Clan's sealing symbol to avoid drawing attention from lower-ranking Yokai.

Moogers

Bio: Moogers, equipped with swords and bows, are the Yokai's foot soldiers. They emerge from between buildings to battle the Samurai Rangers. Mega Moogers are inherently large and have a variant that can fly.

Deker

Bio: Deker, a human cursed to become a Yokai, has a mysterious past. At some point, he proposed to a woman named Dahlia and they married. On their wedding night, after bringing her home, he gifted her a guitar. In return, Dahlia gave Deker a white katana named "Uramasa" and honored him as a "brave Samurai," suggesting his training in Bushido. That night, a fire engulfed their home. Dahlia awoke to flames, and although Deker was missing, she managed to save him. Her cries for help summoned the Yokai King, who offered to save Deker's life. Dahlia accepted, but the king erased Deker's memories, transforming him into a half-Yokai and turning Dahlia into the Yokai Dayu. Deker, reborn but altered, disappeared into the darkness, leaving Dahlia alone.

Serrator

Bio: Legend has it that Serrator, the legendary Yokai King, governed his subjects with an iron fist, aiming to cleave the Earth in two. His ultimate plan was to unite the Earth and the Netherworld into a single realm under his dominion. If such tales are true, he would precede Xandred as the Yokai leader. What is certain, though, is that he commanded a faction separate from the master's.

General Gut

Bio: General Gut is the leader of a group of powerful Yokai who were sealed away three centuries ago by Jayden and Lauren's ancestor. 

Spitfangs

Bio: Spitfangs are formidable monsters from the Sanzu River, surpassing the Moogers in strength. They resemble enormous, skull-like, eyeless crocodilian heads atop two legs and can easily breathe fireballs. Additionally, there exist Mega Spitfangs, which are inherently colossal.