Mystic Knights

• Rohan (portrayed by Lochlann Ó Mearáin) – An orphan raised by the druid Cathbad, Rohan is noble, courageous and steadfast. His weapon is the Sword of Kells, which can emit fire. He also has possession of the Dragon's Breath Dagger, which he uses to summon Pyre, the Dragon of Dare. To win his red and gold Mystic Armor, he had to defeat the Ice Lord of Temra. To don his armor, he shouts "Fire within me!". He is also identified as the mighty warrior Draganta, who is destined to bring peace to Kells for 100 lifetimes. Later in the series, Rohan obtains the ability to become more powerful by the war cry, "Battle Fury!" When he has his armor made powerful in the forge within the Mountains of Gloom, his Battle Fury armor is crimson and gold. Eventually it is also revealed that he is the son of Queen Maeve, with Lugad as his half-brother.

• Deirdre (portrayed by Lisa Dwan) – The princess of Kells. Her weapon is the Whirlwind Crossbow, which shoots a burst of air. To win her white and gold Mystic Armor, she had to defeat the Lightning Bat of Temra. To don her armor, she speaks the words "Air above me!". Deirdre is the most logical-minded of the Mystic Knights, and is therefore sometimes frustrated by her companions' foibles.
• Ivar (portrayed by Justin Pierre) – A black prince from a distant land, Ivar came to Kells in search of his country's sacred chalice. It was later revealed the chalice was stolen by Torc, Maeve's general. His weapon is the Barbed Trident which shoots blue bolts of electricity. To obtain his blue and gold Armor, he had to defeat the Sea Serpent of Temra. To don his armor, he speaks the words "Water around me!" Ivar is loyal to his friends but can be distracted by his search for the stolen chalice, often to his own detriment. He later gains the Defender vehicle (which was meant to be used for Lugad) from Torc.
• Angus – (portrayed by Vincent Walsh) - Angus is Rohan's best friend and a well-known, boastful reformed thief who often gets into trouble. His weapon is the Terra Sling Mace which throws giant boulders and can cause earthquakes. To obtain his silver and gold Mystic Armor, he had to defeat the Rock Wolf of Temra. To don his armor, he speaks the words "Earth beneath me!".
• Garrett (portrayed by Ben Palmer) – Garrett is the prince of Rheged, an ally of Kells. Garrett and Deirdre were promised in marriage and therefore, Garrett first came to Kells to claim his bride. Prior to joining the other knights, he was magically controlled by Maeve, leading him to act against the knights in wicked fashion. However, they eventually freed him with a magic potion and he joined the team. Garrett has a unique ability to command any animal by locking eyes with it, which seems to be independent of his status as a Mystic Knight. His weapons are the Twin Timber Axes which shoot a beam of energy. To obtain his brown and gold Mystic Armor, he had to defeat a giant spider that dwelled in the Banshee Woods. To don his armor, he speaks the words "Forest before me!". In exchange for returning princess Lynette to her homeland, Garrett was given the Dragon Bow Vehicle and he returned with it when the Mystic Knights were facing Lugad. Garrett serves the same role as a "Sixth Ranger" does in many Power Rangers series, supplementing the original team for a time before departing and returning at the climax of their adventures. His storyline is similar to that of Tommy Oliver.

Allies

• King Conchobar (portrayed by Stephen Brennan) – Conchobar is the king of Kells and the father of Deirdre. With Maeve using dark magic to try to help her win the war between their kingdoms, he is in desperate need of the Mystic Knights' help.
• Cathbad (portrayed by Barry Cassin) – A druid and advisor to King Conchobar. He also raised Rohan when he was an orphan. A father figure who did his best to raise Rohan as an apprentice. Cathbad is opposed to Rohan's hanging around with Angus because he tends to cause trouble. He can foresee the future and mentors the Mystic Knights. Cathbad's powers can rival Maeve's, but are limited largely to extra-sensory perception. In "Battle of the Druids", it was revealed that his teacher was Seethchenn who had recently allied with Maeve. Cathbad managed to vanquish his teacher in a druid battle.
• King Fin Varra (portrayed by Peadar Lamb) – The King of Tir Na Nóg. A fairy with great power who gives the Mystic Knights their weapons, as well as occasional advice. He is the rival of the dark fairy Mider.
• Aideen (portrayed by Kelly Campbell) – A sprite who assists the Mystic Knights. She has affection for Rohan and is consequently jealous of Deirdre.
• Princess Lynette (portrayed by Aisling Flitton) - The princess of a faraway kingdom. She became shipwrecked due to an attack by a beast called the Grindon which had been pursuing her for quite some time. Grindon came to the island of Kells in search for her and attacked the kingdom's warriors, and the Mystic Knights; but fled after a lengthy battle. It later attacked the castle, but was repelled by the Mystic Knights. Lynette warned them that it would return at sunset before attempting to leave the castle for their safety, but the Mystic Knights convinced her to stay while devising a plan to lure the Grindon out into the opening. Finally Princess Lynette and Rohan use his sword and slay the Grindon, which she alone could do which as it turned out to be the reason was why Grindon had been pursuing her. After the monster's final defeat, Garrett became her personal escort; with implications of feelings blossoming between them.
• Pyre: Dragon of Dare – An ancient dragon associated with the Mystic Knight of Fire. At first unwilling to tolerate any human presence, he soon comes to admire Rohan and later recognizes the Knight as Draganta, the legendary hero. Fiercely the rival of Tyrune the Hydra. Pyre wears a gem-studded cuirass, through which he presumably makes contact with the Dragon's Breath Dagger wielded by Rohan. His likeness is worked into the Mystic Knights' armor. To summon Pyre, Rohan would hold out the Dragon's Breath Dagger and quote "Pyre: Dragon of Dare, I summon you".

Villains

• Queen Maeve (portrayed by Charlotte Bradley) – Maeve is the queen of Temra. She believes that being the ruler of Kells is her birthright, so she recruits the help of the dark fairy Mider. She is later revealed as the mother of both Rohan and Lugad. In the final battle, she takes over Kells until Lugad frees the captive Knights during her fight with Rohan. She uses her magic to assume the form of a naga-like creature with eye beams. Upon being defeated and regressing back to her human form by the combined powers of Rohan and Lugad, Maeve is banished to another island by King Conchobar. As she sees her son for the last time, Rohan himself asks if Maeve has anything to say to him before she is banished. She then replies that he's been trained well and that he's a great warrior except that he's just on the wrong side. Rohan asks her to be taken away.
• Torc (portrayed by Gerry O'Brien) – Maeve's general who was a former general in Kells before he betrayed them. He stole a silver chalice from Ivar's kingdom, which Maeve needed to enable Mider to travel back and forth between Temra and his realm of dark magic. During the time Lugad was with Maeve, Torc used the Defender vehicle that was meant for Lugad only to lose it to Ivar. In the final battle, he learns that Maeve has been defeated and flees with his army as the Knights have defeated her. As it was mentioned that Torc and his men were last seen fleeing to the woods, Cathbad states that the Temrans are no longer a threat.
• Mider (portrayed by Ned Dennehy) – A dark fairy who helps Maeve with dark magic. He uses the silver chalice from Ivar's kingdom to transport back and forth between a dark realm to increase his powers. After Maeve's defeat and banishment, he aligned himself with the sorceress Nemain.
• The Four Sentinels of Temra – These are the four beings that the Knights had to fight in order to gain their Mystic Armor. They later fell under the control of Maeve, having formerly served their creator Mider.
  • The Ice Lord of Temra (portrayed by Shaun Elebert) – A skull-headed ice lord and Queen Maeve's main general. He fights with a curved ice sword. Rohan fought him in order to gain his Mystic Armor.
  • The Lightning Bat of Temra (portrayed by Ned Dennehy) – A bat-headed member of the Four Sentinels. Deirdre fought him in order to gain her Mystic Armor. He wields a bat-shaped boomerang.
  • The Sea Serpent of Temra (portrayed by Enda Kilroy) – A sea serpent-headed member of the Four Sentinels. He uses a weapon called the Serpent-Tongued Whip. Ivar fought him in order to gain his Mystic Armor.
  • The Rock Wolf of Temra (portrayed by Ned Dennehy) – A wolf-headed member of the Four Sentinels. Angus fought him in order to gain his armor. He wields a set of claws on his forearm and a sword.
• Bogies – Little people who work as spies for Queen Maeve.
• Tyrune – Tyrune is the three-headed hydra of Temra. Maeve tricked Rohan into saying a druid incantation that released Tyrune from his imprisonment. This giant flying creature sometimes attacks without any warning. Often fights Pyre as they are rival dragons. Tyrune's heads can separate from its body and can attack independently.
• Lugad (portrayed by Eric O'Cuinn) – Lugad was brought in near the end of the season. He is half-human, half-demon creature and raised primarily by the sorceress Nemain who was responsible for his mutation. Lugad is the son of Maeve and the half-brother of Rohan. He eventually turns against Maeve to help Rohan defeat her and leaves Kells. Before Lugad leaves, king Conchobar tells Lugad that he is always welcomed in Kells.
• Nemain – The former ruler of Temra until her student Maeve took it over by force. Since that day, she dwelt in a ruined castle and was seemingly content to raise and mutate Lugad on Maeve's behalf. When Maeve retrieved Lugad, Nemain now and then aided the Mystic Knights in the disguise of an old man. When Maeve is defeated, Nemain reveals herself and claims the Silver Chalice declaring her revenge on Maeve complete. Shortly thereafter, Mider proposes an alliance with Nemain to take over Tir Na Nog and Kells. Nemain tells him that she will think about it.

Monsters

These are the monsters that the Mystic Knights battle:

• Ogre (1 and 2) – This was the first monster Queen Maeve summoned in her war against Kells. It can shoot fireballs from its mouth. Maeve used it to attack Kells. It was too much for the army of Kells until Rohan and the others arrived. Following the Temran army's retreat, Maeve sent the Ogre into battle. With a combination of their weapons, Rohan and the others destroyed the Ogre.
• Juggernaut (3) – While Rohan was fighting the Ice Lord of Temra, Queen Maeve created an invincible Juggernaut from a living rock to attack the others. It can shoot boulders from its mouth. Once Rohan had obtained his armor, he helped to destroy it.
• Tash Hound of Temra (4) – When Rohan fell into Maeve's trap, he ended up fighting the Tash Hound of Temra. It was a two-headed dog (similar to Orthrus of Greek Mythology) that can disappear into the shadows. Once Deirdre had obtained her armor, she helped Rohan defeat the Tash Hound of Temra.
• Cyclops (5) – A one-eyed monster with Ipotane-like legs and a lizard-like tail. Maeve sent it to attack a village. Very stupid, but nearly invulnerable. Once Ivar got his armor, the Knights defeated this monster.
• Bull of Temra (6) – After Angus was rescued, Maeve summoned this minotaur-like monster to fight the knights. It has two sets of horns: one set was composed of small stubby horns, and the other ram-like horns. It can shoot electrical-like beams from its small horns. Once Angus got his armor, the monster was defeated.
• Unnamed Creature #1 (15) – Cathbad's teacher Seethchenn predicted that a monster will cross Darkness Loch and attack Kells. At the same time, Maeve summoned this lizard-faced monster with dragon wings, four tendrils for arms and a snake tail for legs to attack Kells. The Mystic Knights fought this monster at Darkness Loch and repelled it.
• Water Creature (20) – A Plesiosaurus/Water Dragon-resembling creature with a long tongue that dwells in the waters in Valley Long. Queen Maeve had it attack Rohan, Ivar, and Angus. It ended up swallowing Ivar. Rohan and Angus tried to get the monster to swallow up Ivar's trident. With Deirdre's help, Ivar got his trident and used his trident to get the Water Creature to spit it out before the Water Creature was destroyed by the Mystic Knights.
• Unnamed Flying Creature (21) – A fire-shooting Stork/Pteranodon creature with ram-like horns. Queen Maeve summoned it to target Prince Garrett. It ran afoul of Rohan and Angus in the first encounter. By the next encounter, Garrett used his special ability to command the creature to return to where it came from and to never to come to Kells again.
• Giant Spider (24) – Garret had to face the Giant Spider in Banshee Woods in order to get his Mystic Knight armor.
• Spectres of the Banshee Woods (24) – When Garrett was told by King Fin Varra that his test to obtain his Mystic Knight armor, Midar summoned 4 of these evil spectres to attack the Mystic Knights. The spectres ranged from an ant spectre, a porcupine/stingray spectre, a trilobite spectre, and a bat spectre. Garrett sought out his armor while the Mystic Knights fought these spectres. Once Garrett obtained his armor, he defeated these spectres.^{[lower-alpha 1]}
• Giant Falcon (25) – Mider gave Maeve and Torc a falcon that will retrieve a map leading to a special dragon egg that Angus recently hid. Upon Rohan and Angus encountering Maeve and her army, she used the Runestone to turn it into a monster. Rohan and Angus don their armors and fight it. Aideen alerts the other knights and Deirdre and Ivar join the battle and repel the Giant Falcon.
• Wyvern (27) – A legless Wyvern who can shoot energy beams from its tail. At first, the Mystic Knights thought the invading Northmen that captured King Conchobar had control of it. It was actually Mider who had the Wyvern summoned on Maeve's behalf to set up the Northmen in a threat to invade the entire island. Rohan, Angus and Garrett engage the Wyvern. As Garrett heads off to rescue King Conchobar from Maeve, Rohan and Angus's attacks weren't even having effect on the Wyvern. It was defeated by Pyre.
• Fire Creature (29) – When Angus was on trial for crimes he did not commit, Mider had Maeve summon a fiery creature to attack Kells. Rohan and Deirdre engaged the Fire Creature. When Ivar catches the real thief hired by Maeve and Angus is declared innocent, they joined the fight against the Fire Creature. With help from Pyre, the Mystic Knights vanquish the Fire Creature.
• Spiked Warrior (32) – After Maeve reclaimed the Silver Chalice from Kells, she summoned this unnamed trident-wielding spikey warrior to attack the Mystic Knights. Rohan, Deirdre, and Angus don their armor and were no match for it. When Ivar fired his trident attack on the Silver Chalice, it shot out energy that destroyed the monster.^{[lower-alpha 2]}
• Phantom Boar (33) – Mider unleashed this ghostly boar to attack King Conchobar and Lady Fionna (who was Queen Maeve in disguise). King Conchobar defeated it easily with one hit from his sword.
• Worm of Woe (34) – To ensure that King Conchobar and King Fin Varra don't fulfill a prophecy where they have to sit on each other's thrones for a day, Queen Maeve unleashes the Worm of Woe upon Tir Na Nóg. It managed to disarm Rohan and Ivar of their weapons and corner them. Aideen arrives to distract it while Rohan and Ivar grab their weapons and armor up. Rohan and Ivar combined their attacks to destroy the Worm of Woe.
• Chimera (38) – When Prince Gann got hold of Maeve's scepter, he used its magic to summon this flying three-headed composite monster with fiery breath. Maeve had Torc evade it to get her scepter. With the scepter recovered, Maeve took control of it and sent it after Gann. The Mystic Knights encountered it attacking Gann. While Rohan went to rescue him, the others armored up and fought the monster. After Rohan reclaimed his sword and repelled Torc, he helped the others to defeat the monster.
• Grindon (39) – This flying, barb-breathing monster is a scourge in Princess Lynette's homeland. It has been pursuing Princess Lynette for quite some time since she wanted Grindon destroyed. Grindon came to the island and attacked the Kells soldiers and the Mystic Knights after it attacked some Temran villages. Upon armoring up, the Mystic Knights' weapons couldn't affect it and it even prevented Rohan from calling Pyre. Torc arrived with his soldiers as Tyrune engaged it in battle. The Mystic Knights used their attacks on Grindon causing it to flee into Kells. It later attacked the castle and was repelled by the Mystic Knights. Lynette warned them that it will return at sunset and if it gets in, the castle will fall. After Princess Lynette left the castle, the Mystic Knights went after her and devised a plan to lure Grindon out into the opening. Finally learning the riddle given to them by King Fin Varra, Rohan has Princess Lynette use his sword and destroy Grindon, which she alone could do (which was why Grindon was pursuing her).
• Evil Eye (40) – Following Rohan being subjected to a potion that fills him with doubt, Queen Maeve summons this laser-shooting, tentacled eye to assist in the attack on Kells. Dierdre and Ivar encountered the Evil Eye and armored up to fight back. Once Rohan regains his confidence, he and Angus help Dierdre and Ivar vanquish the Evil Eye.
• Giant Panther (43) – A large saber-tooth black panther who assisted the Temran army in its fight against the Kells army. It was easily defeated by the Mystic Knights.
• Griffin (43) – To test Lugad to see if he's ready, Queen Maeve summoned three griffins to do battle with him. Lugad manages to defeat them in combat.
• Shadow Monster (48) – Queen Maeve summoned this shadowy monster to assume the form of Lugad in her attack on Kells. Dierdre, Rohan, and Garrett managed to see through its disguise and armored up. They drove the Shadow Monster out of Kells as Angus and Ivar show up. They combined their attacks and destroyed the Shadow Monster.

Voice actors

• Ned Dennehy as The Lightning Bat of Temra, The Rock Wolf of Temra
• Shaun Elebert as The Ice Lord of Temra
• Enda Kilroy as The Sea Serpent of Temra