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Viper (バイパー, Baipà) is the holder of the Mist Arcobaleno Pacifier. He is a member of the elite Vongola assassination team, Varia, under the name Esper Mammon (精子•マーモン, Espā Māmon). Known as the Varia's best spell caster, Viper has the ability to cast illusions as well as being able to locate any person by sneezing into a piece of paper (he carries a roll of paper with him); the spit or mucus that sticks to the paper shows a map leading to the desired person. Other than for the exception of the Arcobaleno Trials, Viper only works for money and is therefore represented as the sin of greed in Varia. He also has a dark green frog named Fantasma that lies on top of his head. By turning into a yellow ouroboros (a snake devouring its own tail that is also an alchemist's symbol) into a "halo" above him, Fantasma can give Mammon the ability to fly in combat; He claims to have been trying to break the Arcobaleno curse, and had sealed his pacifier so that other Arcobaleno cannot sense him with the Mammon Chain, which also seals the power of Rings and Boxes and such. The chain is replaced by the Vongola by the cap that conceals the Rings' powers the same way as the Chains.
Both as an adult and in his Arcobaleno form, Viper is shown wearing a black outfit with a hood that covers his eyes making it hard for fans to know his gender. From what little can be seen of his apperance before becoming an Arcobaleno, Viper had chin-length purple-lish hair and fairly white skin. He has two up-side-down triangle purple markings on his cheek that extend when he uses his Arcobaleno powers.
As an Arcobaleno, he carries with him a roll of what seems to be tissue and uses it to create illusions to attack his opponents.
Plot OverviewVaria's plan in the beginning was to find all of the Vongola half-ring bearers on Tsuna's side and take the half-rings by force. Viper used his thoughtography to help the Varia members locate their equivalent member on Tsuna's side. Before a fight happened, CEDEF interupted and it was explained that there would be an official battle for the rings. Members on both side will fight for the other half of their ring against the member on the opposite team who has it. Being bearer of half of the Vongola Mist Ring, Viper fought against the corresponding Mist guardian, Chrome Dokuro. He revealed himself as the Mist Arcabaleno and easily bested Chrome. When it seemed over, Chrome switched bodies with Rokudo Mukuro. Viper at first didn't believe it was Mukuro because he had heard of his imprisonment at Vendice, but he soon came to realize it was. Being the Mist Arcobaleno, the strongest illusionist, he was frustrated when Mukuro was overpowering him. He asked where Mukuro got this talented and Mukuro responded that he got his powers from Hell itself, irritating Viper, who didn't believe him at all, to the extreme. Viper was defeated and seemingly exploded, but Mukuro revealed that Viper had survived because he had reserved enough energy to escape as a precaution. As things progressed and events happened, Varia members are shown to have caught Viper from wherever he was regenerating to help fight at the main battle of the Ring Conflict, where whichever boss gathers all the rings first will suceed as the 10th Vongola Boss. As Xanxus and Tsuna fought, all the guardians were poisoned with a paralyzing illness that only obtaining the ring of their type would give them the antidote. Varia member Belphegor came and healed Viper and they set up a plan for getting all the rings by holding Chrome hostage. Their plan suceeded and even though their boss had lost against Tsuna, they gave him all the rings to seemingly take the win. The Vongola Rings rejected Xanxus and it became known that he didn't actually have Vongola blood. The Varia was disqualified but Belphegor revealed that backup was coming, backup that was only bested by the main Varia members. Three people arrived, nearly unconcious, and reported that all the rest had been defeated by Lancia. Being the only two members of Varia left able to fight, and being surrounded by all 6 of Tsuna's guardians, Belphegor and Viper surrender.
Viper and the other Arcobaleno are called by Reborn to train Tsuna and the others. Viper is paired up with Chrome as his student. But, it seems that Viper hasn't taught anything to Chrome due to the fact that he doesn't get paid. So, right after he comes back, after hearing his insults from Skull, he leaves. However, he comes back when Colonnello was searching for him and later helps Chrome to break Daemon Spade's Illusion. After Daemon and Giotto gave Chrome and Tsuna their inheritance, Chrome thanked him for saving her, and he said that she had improved, somehow. Shortly, he was picked up by Squalo and Belphegor who had searched for him everywhere because there was a job that required an illusionist.
At the ceremony, he noticed that Dino and Squalo had seen through Chrome's illusion of Yamamoto; however, he tells her that an illusion of that level can be only seen through by experts and assures her that she was doing well. At the last minute right after Tsuna and the others were defeated by the Shimon, he and the rest of the Varia along with Dino and Reborn, tried to stop the Shimon but was stopped by their tracks by Adelheid. Squalo requested for him and the rest of the Varia to chase after the Shimon right after they took Chrome away, but the Ninth order them not to chase after them.Pacifier Spring that was located near the area which could strengthen the light of pacifier, which could perhaps allow him to read the rest of the letter, and decides to go there along with the other Varia except for Xanxus. Viper and the others found Mukuro and the Kokuyo Gang also trying to recruit the young Flan, but Viper leaves soon afterwards, saying he couldn't care less about Flan. Viper heads to Pacifier spring and finds the other Arcobaleno, Fon, Colonello, Skull, and Verde. They said that some of the letters were unreadable, which can explain why some of the unreadable words on Viper's letter were not caused by the food. They say they should stack up the letters for the missing words to fit. After that, they know the information Reborn got during the battle against Daemon Spade, including the one about the mysterious Arcobaleno from the Vindice. Viper strangely knows about the Arcobaleno with the transparent pacifier. Viper, along with the other Arcobaleno, minus Aria, are in a dream they are all having. They meet the mysterious man that they met before they became the Arcobaleno. The man asks if they want to be freed from the curse of the rainbow. Viper shows himself to be very passionate about breaking the curse, saying that it's been his dream for many years. The man says that the Arcobaleno that gives the best contributions will be released from the curse; he then reveals that the one that shows himself to be the strongest will be considered worthy. He states that the Arcobaleno cannot personally fight for themselves, but must get representatives to fight for them. Viper is then shown back at Varia headquarters requesting assistance from Xanxus, who replies that it depended on the situation, but is later on revealed to have accepted. He is later seen by Dino in Japan with the rest of the Varia, who were staying in the same hotel as the Chiavarone Famiglia. Mammon is later seen in their residing hotel riding on Belphegor's head as he kidnapped Tsuna, calling Tsuna a brat; a while later, after Tsunomichi arrives in the Varia's hotel room, Mammon connects the former's appearance and clothing to Checker Face's. He then listens to the rules of the Representative Battle of the Rainbow.
Later, on the second day of the Representative Battle of the Rainbow, Mammon tries to get Xanxus to fight Team Fon when they came to challenge them. Mammon is successful and watches the battle, but is forced to release his curse with his Rainbow Wristwatch and use Hyper Mirage R to stop Fon from eliminating Xanxus and eliminating them from the battle, and announces that the rule he set for the battle was that the side that doubted their victory would self-destruct. He sent Fon and himself into illusionary space that he created and started to fight him one-on-one. However, Fon easily destroyed his illusions, making him doubt to win. Fortunately for him, Fon's curse release time has reached its limit and he returned back to his baby form. Seeing this chance, Mammon freeze Hibari's legs to prevent him from escaping Xanxus' attack, but Dino saved Hibari before the attack hit him. Xanxus ordered Mammon to stand back since he's injured. Mammon at first protested, but then reluctantly obeyed when Belphegor said that he wants to fight alone.
After the second battle ended with a draw, he, and the other Arcobaleno were shocked to see Bermuda along with seven Vindices joining the Representative Battle of the Rainbow as the eighth team. Shortly after, he and the other Arcobaleno visited Skull at Namimori Hospital and discussed about Bermuda, but found nothing about him. He then questioned Reborn his reason to join the Representative Battle of the Rainbow, but Reborn refused to answer and instead told him to ask Fon and Yuni. After the meeting is dismissed, he went back to the hotel and surprised to find his team was assaulted by a Vindice.
Weapons and Abilities
Before he was turned into an Arcobaleno, he was a first-class psychic who added Illusions to his repertoire. It was seen he could also fly before he was turned into an Arcobaleno. His psychic ability was telepathy, and he could also dowse things through pieces of paper so that he could find objects and people. As an Arcobaleno he still has all of his powers, but his Illusions have been strengthened, possibly because the Arcobaleno Mist Pacifer is an object of the Tri-ni-set that emits Mist Flames, creating real Illusions, and giving the wielder the Arcobaleno's ability to emit Dying Will Flames from their bodies. On one occasion, he even showed that he could teleport.
- Illusions: As the Mist Arcobaleno, his Illusions are first class; the only time he was defeated by another Illusionist was when he fought Mukuro during the Mist Ring Battle. His most commonly seen used Illusions are Illusions of clones of himself and the Illusion of tentacles.
- Viper Mirage: One of Viper's many Illusion abilities; he used this to surround Namimori with a series of mirages.
- Viper Mirage R: One of Viper's illusions that sets a rule on the target of which the illusion is cast on. If the rule is broken by the target, the target is instantly damaged with a multitude of deep cuts.
- Telepathy: One of his psychic abilities is telepathy, the ability to read minds.
- Thoughtography: The ability to locate any person by sneezing into a piece of paper; the spit or mucus that sticks to the paper shows a map leading to the desired person.
- Flight: Viper can fly because of his Animal Partner Fantasma's abilities, but he has been shown to be able to fly without Fantasma's assistance.
- Uroboros: Declared by Viper himself to be his strongest illusion, Viper unleashes multiple large blind eel-like creatures with large mouths and sharp teeth.
- Mist Starfish: It was one of the first Box Weapons that were created and appeared in the past. It was used by Viper against Yamamoto and Ryohei during the 3rd Trial. When used, many spinning Starfish that emit Mist-Flames come out of it. Those that break are fused together and create a single and bigger Starfish.
- The word "Mammon" is a term used to describe material wealth or greed, most often personified as a deity.
- He dislikes being called by his given name, Viper. However, he doesn't seem to be bothered if Reborn calls him by that name.
- Mammon's favorite drink is strawberry milk.
- Mammon dislikes leaving his debts unpaid.
- The reason why Mammon collects money is because a human repeats the same life eternally.
- Mammon's gender has been a debate among fans due to the use of gender-neutral pronouns used to describe him. He was grouped into the male character category in the third popularity poll, and his gender continues to remain as male in the official VIZ translations.
- Mammon has a character song: Maboroshi no Arcobaleno.
- In the official English translation, Reborn and Colonnello said that his Arcobaleno Pacifier had a "sunny glow."
- In Drama CD: Namimori Radio, it was revealed that he and Belphegor once borrowed one of Leviathan's parabola when it was raining, but ended up being struck by lightning.
- In Haru Haru's Interview: Dangerous, it's revealed that like Fon, he cannot eat Mapo Tofu since he was turned into baby because it was spicy, which makes him choke and tear up.
- Mammon only likes to work if he gets paid, on a rare occasion, Mammon works for free only if the situation is dire or it is his duties as an Acrobaleno, although he complains.
- Mammon and Belphagor appear to be very close, as Mammon avoids most of the Varia members and is mainly seen with Belphagor.