|This article contains canon information corresponding to the Tales of Arcadia franchise. That means all information in this article is true and has appeared/been validated officialy on-screen.|
Merlin is the original creator of the Amulet of Daylight, which became passed down in the Troll society for thousands of years and a legendary wizard who is known for his might and power.
It is said that Merlin had mentored and aided Arthur Pendragon in taking his rightful place as ruler of Camelot. He also had an apprentice, a young woman by the name of Morgana Le Fey, and together they experimented with all sorts of magic, Merlin not realizing that his pupil was turning towards a dark path.
It is uncertain what happened, but before long Morgana betrayed her former mentor, he took her left hand and used it to craft the Amulet of Daylight to help the Trolls in their struggle against Gunmar the Black and his army of Gumm-Gumms.
Merlin was present during the Battle of Killahead, dueling against his former student while the Trolls, led by Deya the Deliverer, fought Gunmar and his forces. Expending much of his magical powers, Merlin imprisoned Morgana and then retreated to his Tomb where he fell into a deep sleep, waiting for the day he would be needed again.
However, he did not realize that while he slumbered, Morgana remained awake and spent the next thousands of years plotting her revenge and ultimate conquest.
Merlin appears to Jim as an illusion created by Unkar the Unfortunate, where Draal becomes Trollhunter in Jim's place, to convince Jim why he is destined to be a Trollhunter. Once the illusion progresses to the point where Draal fails to prevent Gunmar's escape from the Darklands, Jim finally ignores Unkar's pleas to think of himself, at which Merlin appears, pleased at the boy finally understanding the lesson he was trying to convey. Jim soon realized Merlin's identity when he revealed his connection to the amulet. After insisting that Jim kneel before him, Merlin stated that of all the creatures on Earth, he chose Jim as his Trollhunter and reminds him that in the real world, Gunmar is loose and Heartstone Trollmarket is in danger.
Gunmar, accompanied by Angor Rot and Draal the Terrible (still under Gunmar's control) journeyed to find Merlin's Tomb to obtain the Staff of Avalon in his plan to bring about the Eternal Night. Jim, Claire, Toby, Blinky, and AAARRRGGHH!!! tried to stop them but it ended with Gunmar successfully claiming the staff and Draal's death.
As the caves of Merlin's Tomb began to fracture, the heroes tried to find a way to escape. When they came upon the true tomb of Merlin and found the wizard himself, who awoke, having never been dead, to begin with.
Merlin, using an illusion spell, reveals he was there during the Battle of Killahead Bridge, fighting against Morgana, against whom he used most of his magic in order to imprison her. With Merlin's help, they all escape and return to Arcadia, where Merlin is amazed by the changes and advancements of the modern world.
While he gets settled into the Lake Residence, Merlin sends Jim, Claire, Toby, Blinky, and AAARRRGGGHH!!! out to find a list of ingredients, some of which he uses to craft suits of armor for Claire and Toby (albeit using Jim's Vespa).
He later reveals to the kids that he wants Morgana to be freed in order to end her threat forever, but also because he hopes in doing so he'll regain all of his magical powers. He comes to odds with Jim, whom Merlin easily defeats in a clash before subduing the young Trollhunter and revealing the ingredients he sent them out to collect weren't just so he could craft more armor, but also to make some kind of mysterious concoction.
Later, he has an honest yet tense conversation with Jim, revealing that Jim is not strong enough to defeat Gunmar even with the Sword of Eclipse, but he can be...if Jim becomes something more than human. He explains that the potion is meant to transform Jim, to make him half humand and half troll, to increase his abilities. Although there is great tension between them, Merlin tells Jim that the choice is his of whether to use the potion or not, but also warns him that the transformation will be permanent and while half of Jim will stay the same the other half will change forever. That night, Jim starts to feel reluctant and scared about changing into a troll. He goes into the bathroom and pours the potion into the bathtub. While the others try to convince him not to go with the transformation, Jim begins to reflect on everything that has happened since he got the amulet. After thinking it over for a while, Jim goes into the tub, where he begins to transform into a troll.
When Jim becomes his new self, he begins to enjoy his new enhanced strength, stamina, and speed. However, he also realizes that since he is not human anymore, he can't go out into the sun, eat human food, or go to school with his friends. Jim becomes extremely depressed and begins to have an identity and existential crisis. The others become greatly concerned and chew Merlin out for convincing Jim to change his form.
Merlin, Barbara, Blinky, AAARRRGGGHHH!!!, Claire, and Toby go to the rooftop of the school to comfort Jim in this big change in his life. They explain to him that while he may look different and has lost his humanity, they still love and care for him, and he is the same person on the inside. Merlin then commends them for their loyalty and declares to prepare for the Eternal Night, which will happen at sunrise.
As soon as the day comes, Merlin comes up with a plan to kill Morgana before the Eternal Night begins: he and Jim will infiltrate Trollmarket and attack her before she can gain full power. Blinky believes that it is a bad idea because while they are attacking Morgana, Angor, and Gunmar will be free to attack all of Arcadia. Jim stops the argument by saying that Toby and Claire will clear the Arcadia square (where everyone in town will be for the Battle of the Bands contest), while Merlin and AAARRRGGGHHH!!! go to Trollmarket to stop Morgana. Jim has to stay home until night falls, otherwise, he's likely to be burned to crisp.
As soon as the Eternal Night begins, Jim watches the sun being blocked and is ready to fight Angor and Gunmar. Merlin and AAARRRGGGHHH!!! go to Trollmarket to find Morgana, only to encounter her minions. With the help of the spirits of the past Trollhunters, they manage to defeat the Gumm Gumms.
Merlin is an old wizard with the stereotypical white beard and eyebrows. He appears to wear armor that looks just like Jim Lake’s but differs in the regard that it is colored green.
Merlin is a wise, yet rather eccentric wizard, even somewhat flirting with Clarie, a 16-year-old girl. He has a tendency to make sarcastic comments to the people around him, especially Blinky and he is easily amazed by the wonders of the modern world. He easily gets on the gang’s nerves. Despite his eccentric ways, Merlin is very competent in battle and is amazing at magic spells and hexes.
There is a dark side to Merlin, an arrogance to him where he believes his many years of experience means that he knows better and that any who disagree with him are just ignorant or too young to understand his jaded views and less than forthcoming methods, as he showed in a very tense heart-to-heart he had with Jim, in whom Merlin saw perhaps a younger and more optimistic version of himself. He claims he once had faith as pure as Jim's but became jaded and harsh in his views, but left a great decision in Jim's hands (although it can be argued that he manipulated Jim into doing so). There's also the fact that he has trouble improvising at times when his long-term plans go sideways due to his own failure to foresee certain changes in circumstances, such as Morgana rendering his Staff of Avalon useless or that a Trollhunter's abilities would be worthless against a wizard like her.
Powers & Abilities
Merlin is among the most powerful beings in the series although, after his duel against Morgana in the Battle of Killahead, he lost much of his magic and went into a slumber in case he was ever needed again.
Regarded by both humans and trolls as the greatest wielder of magic to ever live, Merlin is a wizard of great legend. His knowledge of mystic lore and skill in wielding magic can only be challenged by his former pupil Morgana.
However, after their prior duel at Killahead, he lost much of his power. Even so, after waking up, he is still capable of some impressive magicks which he calls parlor tricks, such as making an illusion to illustrate the role he played in the Battle of Killahead, moving objects without touching them, locking doors with a flick of his fingers, conjuring a sword, and so on.
He is a skilled alchemist and potioneer, as he made a potion that would transform Jim into a Human/Troll hybrid.
Merlin has the gift of seeing the future, although it is not always an exact science. He was able to foresee the arrival of Jim and his friends to his tomb 200 years before it happened.
Besides his mastery of magic, Merlin is skilled in craftsmanship and blacksmithing, evident by his creation of the Trollhunter amulet, the Trollhunter armor and the Sword of Daylight, and later new suits of armor he crafted for Claire and Toby. It can also be said he is an architect, evident by his lair and tomb beholding all manner of traps and mechanisms.
Much of his work involves magic, such as how his tomb undid any foreign magicks that entered (such as the mind-control of Gunmar's Decimaar blade over Draal).
Even without his magic, Merlin is a true warrior, wielding a sword of his own making to easily out-duel Jim, a skilled swordsman himself, to the point where it is clear the wizard was toying with him.
- Merlin is confirmed to star in the upcoming series Wizards, the conclusion to the Tales of Arcadia trilogy. 
- Merlin is based on the wizard of the same name from the King Arthur folklore.