Serrator

Serrator was the villain in Power Rangers Samurai. He was referred to in legends as the Nighlok King. He was the one that cursed Dayu and Deker to live on as Nighloks. He has since recruited both Dayu and Deker, while also offering to fix their broken items.

Serrator is unknown to Master Xandred and Octoroo. He sends heralds to 'help' Xandred try and defeat the Samurai Rangers, such as Switchbeast. Soon he makes himself known to Xandred, not as a king, but as a Nighlok who's been trapped for so long, and had been only recently freed and powered up by surges in the Sanzu River. He offers his services to Xandred, who he calls 'master' and vows unflinching loyalty to him. In addition, he brings with him new Moogers eagerly awaiting his orders. He makes himself known to the Rangers where none of their attacks were able to harm him. Serrator even cuts a piece of paper into a shape and transforms it into Papyrox. When Antonio Garcia arrives and manages to harm Serrator, he leaves stating that the Rangers "passed the test" for now.

Serrator would attack the Earth, with his Papyrox, for a second time. During the second attack, he was also aided by stronger, different colored Moogers and Spitfangs, as well. As with his first attack on Earth, he and his minions were defeated.

He threw a dark spell in the island of Monolua to make them all fight each other. Also to make the Sanzu River rise. When the Samurai Rangers arrived to the island, Serrator had Deker, Dayu and himself split into threes just so they can defeat the rangers. When he found out the rangers survived the attack, he sent Malden and his master blasters, only for them to be defeated by the rangers and the new weapon they acquired the Bullzooka. Then the rangers put out the fire (Serrator made to throw a dark spell) with the Bullzooka. As a last ditch effort, he sent a Papyrox along with two Spitfangs, only for them to be defeated and Serrator's plan thwarted.

Later, Dayu began to tire of waiting for her Harmonium to be fixed, while Master Xandred's headaches were becoming worse without Dayu's music. Serrator went to fetch the Harmonium, however Octoroo tagged along to ensure he would be true to his word. While on Earth, Serrator revealed he had his own agenda, one which didn't involve Xandred or Dayu, however her Harmonium was essential in his traitorous motives. Octoroo briefly fought Serrator, before leaving to inform Xandred of Serrator's treachery. Serrator was then attacked by Dayu, who wanted her harmonium back, and the Rangers in an attempt to destroy him. Suddenly, Master Xandred arrived on Earth despite the fact that he would quickly dry and weaken. Seeing he was outnumbered, Serrator fled. Due to severely drying out, during his time on Earth, Master Xandred was forced to completely immerse himself in the Sanzu River, for an indefinite amount to time. While Xandred was hydrating, at the bottom of the Sanzu River, Serrator easily took command of Xandred's ship.

Eventually the rangers discovered that all of Serrator's attacks form a line. During the next battle, Serrator explained the meaning of the line to the rangers which is to have Deker cut the Earth in two just so Serrator can rule both Earth and the Netherworld, which he intended him to do once he returned Uramasa to him as payment. When all the wedges were set, Serrator located the weakest point between Earth and the Netherworld. When Deker arrived to the spot, Serrator returned Uramasa to him, just so he can strike the final point before it explodes. However Deker instead slashed Serrator, revealing that all he had wanted was Uramasa repaired and didn't share the hatred of humanity that most other Nighloks shared before leaving. Serrator was enraged and attempted to take out his wrath on the Samurai Rangers, however his first form was destroyed by a Five-Disk Octo Cannon and Super Bullzooka combo. Transforming into his Mega Monster form, Serrator with the help of 2 Papyroxes took on the Samurai Megazord, Claw Battlezord, Bull Megazord and Lightzord. Eventually the Samurai Megazord and Claw Battlezord defeated the 2 Papyroxes. Then the Rangers formed the Samurai Gigazord but found that even that wasn't enough to defeat the Nighlok King, so summoned the Shark Zord for assistance. Combining into the Samurai Shark Gigazord, the Rangers were finally able to destroy Serrator. Before exploding, Serrator complained that he was supposed to split the world open, not get split in half himself.

Powers and Abilities
Serrator is an extremely powerful Nighlok (surpassed only by Master Xandred), who possesses many abilities such as:
 * Emit lightning
 * Grow and extend his claws
 * High speed strikes
 * Create monsters from paper kirigami
 * Capture an energy blast, infuse it with more power and send it back
 * Highly skilled hand-to-hand combatant
 * Curse inducement
 * Teleportation

Nighlok Servants

 * Switchbeast
 * Crustor
 * Skarf
 * Dayu (former, as of "The Master Returns")
 * Deker (former as of "Stoke of Fate")
 * Duplicator
 * Grinataur
 * Epoxar
 * Maldan
 * Pestilox

Trivia

 * His counterpart in the Super Sentai series that Samurai was based on is Akumaro Sujigarano.
 * In "Broken Dreams", he's credited as Mysterious Shadow.