Myū of the Butterfly

•Ugly Eruption: This is a technique that Myū of Papillon uses in his first form (his chrysalis form). It consists of expelling jets of gas towards the opponent through the protrusions found on his slimy body. This gas or corrosive liquid hits the enemy's body, causing damage. •Silky Thread: This is a technique used by Myū of Papillon in his second form (his caterpillar form). It consists of throwing a large quantity of fine, strong threads from his mouth that envelop his victim, trapping them in a cocoon. These threads and the cocoon they create are very resistant, so much so that even a powerful Gold Saint like Mū took several minutes to destroy the cocoon from the inside. The cocoon created by this technique removes all the oxygen from its interior and blocks the entry of oxygen from the outside, which can cause the victim of this technique to die of suffocation in a short time if they cannot destroy it in time. •Fairy Thronging: This is Myū's main technique after reaching his final evolution, and also that of those who wear the Papillon Surplice. In this technique, the Specter concentrates his cosmos in his hands to summon a large number of underworld fairies. Then, he begins to move his hands while the butterflies surround his opponent's body. In this way, Papillon's cosmos and the fairies immobilize and float him, then create a large column of light that sends him, body and soul, directly to Yomotsu Hirasaka. Once there, the fairies drop him directly into the hole leading to the Underworld, causing his death.

Myū attacks with his Ugly Eruption, then Mū protects himself with the Crystal Wall. Myū is surprised that the Ugly Eruption doesn't work and Mū counterattacks with his Stardust Revolution. Myū receives the blow but emerges in the form of a worm, attacking Mū with his Silky Thread, wrapping him up and trapping them in a cocoon. Mū manages to free himself from the technique and discovers that there is another cocoon. Inside the cocoon, Myū tells him that he knew he would free himself from the Silky Thread but that he wrapped him up only to buy time and reach his final form. Immediately Myū emerges from the cocoon with a Surplice in the shape of a butterfly. Suddenly a large number of butterflies appear. Myū explains that they are the butterflies of the underworld, the Fairies, who will accompany Mū to the underworld. He fights Mū, where the Gold Saint demonstrates his high level of Psychokinesis, throwing him against the walls and ceiling of the Cancer Temple, then dropping him to the floor and finally spinning him at high speed with the intention of killing him, but he ends up freeing himself thanks to his Fairies. In Mū's attempt to escape, he is pursued by Myū in a race of teleportations, the Specter unknowingly falling into an invisible crystal net that Aries created. In this way, Papillon was disintegrated along with his Fairies after the devastating attack of the Gold Saint.

At some point, Itia encountered Thanatos, Hypnos, and Myū in the Kyōkō Chamber. Later, he would awaken the Kyōkō Chamber, telling Gateguard he was wrong and that people would never change. Immediately afterward, the Pope informed him that with the power he possessed, he would judge the Earth, and asked the Aries Saint if he would stop him. The Aries Gold Saint replied that he was right and expressed his determination to sacrifice himself for Itia's ideals if necessary. Myū manipulated Itia to win the war, but Myū was ultimately killed by Sage of Cancer. Hundreds of years later, he appeared in the Cathedral of the Forest, preventing the Silver Saints who were there from leaving. Later, he appeared during the invasion of the Childhood Village of Tenma, Sasha, and Alone. He reappeared at the Specters' meeting, but was ambushed and killed by Regulus of Leo with his Lightning Crow. 247 years later, Myū returned to life once more. Myū of Papillon is one of the Specters sent by the Judge of Hell, Rhadamanthys, to the twelve Temples of Athena's Sanctuary to watch over the Gold Saints resurrected by Hades. Myū appeared in the Giant Crab Temple, paralyzing Mū of Aries with his psychokinesis; Mū had been pursuing Saga, Camus, and Shura. Appearing in larval form, Myū ordered a group of Specters commanded by Giganto of Cyclops to go to the Lion Temple, while he would deal with Mū. When the three were alone, Myū released Mū from his psychokinesis to fight on equal terms.

Myū is very special among the Specters, as he gives us a speech and explanation about the nature of the Specters, assuring Mū that they are humans and not ghosts. Like all Specters, Myū trusts in his powers, but unlike many of them, Myū actually possesses the powers he claims and therefore makes a very good impression on a martial level. Unfortunately, he also underestimates his opponents, and his desire to face Mū of Aries in a single duel is motivated more by personal pride than by honor. Myū likes challenges, and having heard about Mū's psychokinetic abilities, he tries to measure his own abilities against those of the Aries Saint. This pride even makes him forget his mission as a Specter.

Myū's appearance is unusual among Specters due to its unhuman look. Myū has four evolutionary stages. First, it appears as ectoplasm, a kind of dark, viscous mass surrounded by several boils. Then it transforms into a horrifying worm-like creature with dark colors and large green eyes. After going through its chrysalis stage, Myū adopts its final form: that of a man of medium height, slender build, and beautiful appearance. It has long, spiky, dark pink hair and special eyes, similar to those of an insect.