Mephiles the Dark is one of the main villains of the game Sonic the Hedgehog (2006). He is the conscious, mind and will of the Sun god Solaris, ultimately making him the main antagonist of the game's story.
Mephiles is the final boss of Shadow the Hedgehog's story, although he plays a pivotal role in all three of the game's storylines. He is a skilled manipulator, tricking Silver into believing that Sonic was the Iblis Trigger and thus that killing Sonic would save Silver's future. He also has a particular interest in Shadow, who originally imprisoned him after his creation, and whose appearance and powers Mephiles absorbed upon his release. Mephiles repeatedly attempted to convince Shadow to join him, but Shadow refused each time.
He is famous for being the only character in the various Sonic continuities to actually succeed in killing Sonic.
Physical Appearance
Mephiles has three forms. Its original form was an amorphous mass of darkness. In his second form, Mephiles appears almost identical to Shadow the Hedgehog, aside from having green eyes with slit pupils, no visible mouth (though his muzzle moves when he speaks, as if he does have a mouth), and the fact that everything that is red on Shadow is a pale powder blue on Mephiles. His third and most common form was a crystalline, anthropomorphic hedgehog. In this form, he has no visible nose, mouth, or feet.
An image of Mephiles looking identical to Shadow.
An image of Mephiles in his third form.
History
Mephiles was accidentally created during the Solaris Project, under the supervision of the Duke of Soleanna. In one of the Project's experiments, Solaris was split into two separate entities: Iblis, its raw power, and Mephiles, its cunning mind. Mephiles was sealed in the Scepter of Darkness by Shadow the Hedgehog, who had traveled through time to ten years before the events of the game.
In the intervening years, Doctor Eggman somehow acquired the Scepter of Darkness. In the present day, the Scepter was shattered during a struggle between Eggman, Shadow and Rouge, and Mephiles was released. Mephiles then transformed into a copy of Shadow by absorbing Shadow's shadow, and in doing so absorbed Shadow's powers as well. Realizing that Shadow did not know who Mephiles was (as Shadow had not yet travelled back in time to face Mephiles in the past), Mephiles transported Shadow and Rouge into the future.
Mephiles then sought to find the Chaos Emeralds and bring pain and despair to Princess Elise, in order to release the "Flames of Disaster" (a.k.a. Iblis), who had been sealed inside Elise's soul until she cried. Mephiles intended to fuse with Iblis, reuniting them into a single entity, Solaris.
To accomplish this, he told Silver the Hedgehog and Blaze the Cat that Sonic the Hedgehog was the cause of Iblis being released, which led to the destruction of their world. Sonic was, thus, referred to as the "Iblis Trigger". He sent the two back in time, making them believe that killing Sonic would save their future.
Along the way, as all three storylines progress, the three main characters discover how Mephiles was somehow involved in the incident which created the "Flames of Disaster", wielded by Princess Elise. Mephiles has a very pivotal role in all of the storylines, throughout the course of the game. He has the most direct role in Shadow's Story. He also has a major role in Silver's Story, as he manipulates Silver and Blaze into attempting to kill Sonic so that he can finally fuse with Iblis. While he himself has a very minor role in Sonic's Story, where he is only seen when Sonic, Knuckles, and Tails are eavesdropping on his conversation with Silver and Blaze that ends with them time-traveling back to present-day Soleanna, his actions are still very much prevalent to Sonic's Story, especially with his encounters with Silver. Mephiles attempted to break Shadow's will to fight and join him, much like Black Doom had, by revealing that in the current future, the world and an unwilling Omega would turn against Shadow and imprison him in suspended animation (Mephiles keeps his hatred for Shadow a secret). Thus, he attempted to get Shadow to join him, saying they would both get revenge on the world. However, Shadow proved immune to Mephiles' tactics, saying that he would determine his own destiny, leading to a battle between the two of them. Though Shadow took the upper-hand, Mephiles knocked him into a wall with an energy blast and incapacitated him when he lowers his guard, but Omega intervened and drove Mephiles off. Later, Omega met Mephiles again, who revealed to Omega that he was one that would imprison Shadow in the future, prompting the robot to shoot him with two miniguns. As Shadow (along with Silver after Shadow foiled his second assassination attempt on Sonic) had traveled back into the past at that point, he learned of Mephiles' true nature (and Silver learned that Mephiles had lied about Sonic being the Iblis Trigger).
Shadow, Omega, and Rouge later meet Mephiles in the desert temple. Again, Mephiles offers Shadow a chance to join him, but Shadow, knowing Mephiles' true intentions, flat-out refused the offer. Mephiles was fought again and lost. After his seeming defeat, however, Mephiles proved immune to being imprisoned in a new Scepter of Darkness that Shadow tried to use on him, saying that it wouldn't work on him anymore (he implies that the reason he was immune was due to his time traveling to ten years ago, due to his line of "The "I" of now absorbed your power through your shadow in the past."). Mephiles then uses two Chaos Emeralds to create an army of clones of himself. He then boasts to Shadow that he can't defeat him, and asks why he is even bothering to protect a world that will eventually turn against him. Shadow responds by saying, "If the whole world decides to become my enemy, then I will fight like I always have", and, mirroring a similar ability from the Sonic X adaptation of Sonic Adventure 2, removes his bracelets and destroys the entire army in a massive burst of energy.
In the Last Story, Mephiles, having either escaped or simply survived the fight with Shadow, finds the purple Chaos Emerald, uses it to warp to Sonic and Elise's location shortly after they escape Eggman's exploding Egg Carrier, blinds them with the Emerald's powers, and projects an energy spear that impales Sonic through the back, killing him instantly. Elise cries over his death and, as a result, releases Iblis, allowing Mephiles to fuse with him and transform into Solaris (who is soon destroyed during a battle against Shadow, Silver and a revived Sonic in super form).
It is also revealed in the Last Story that Mephiles' lie to Silver and Blaze about Sonic being the Iblis Trigger was partially true: Sonic is indeed the Iblis Trigger, but his death would not stop Iblis's resurrection; in fact, his death would be the very event that would release Iblis from Elise's soul. The key to Iblis's freedom was an event that would cause Elise to become so consumed with despair or guilt that she would cry, as she had formed a very close friendship with Sonic.
Due to Sonic and Elise's actions in the past, Mephiles was erased from existence.
Personality
Unlike most of the villains in the Sonic series, who are driven by a lust for power or revenge, Mephiles (as Shadow stated) only seems to crave destruction. He is portrayed as a cold, ruthless villain with no sense of compassion. He would do anything to accomplish his goals, even if it means taking innocent lives. Mephiles happens to take great pleasure and delight in hurting others and has been shown to have a very warped and twisted sense of humor, making him a very sadistic and psychotic individual. For example, he made it his sole mission to cause pain to Elise throughout the entire course of the game, and even broke out into a maniacal laughter after ending Sonic's life. This is also seen when he taunts Omega by telling him he would be reprogrammed to capture Shadow. Mephiles also happens to be highly intelligent, as he's capable of using and manipulating people to further his evil plans. This is shown when he preyed upon Silver's frustration and desire to save the world, by deceiving him into thinking that Sonic was responsible for everything, knowing that killing him would have done the exact opposite of what Silver was trying to achieve.
He also has nihilistic tendencies, as evidenced in his final fight against Shadow, where he asks why Shadow even bothers fighting at all, and why Shadow even bothers defending humanity when they will inevitably persecute him later.
It has also been speculated that Mephiles might also be somewhat of a coward, judging from several actions he displayed throughout the game:
* He operated most of his plans secretively, and his main target, Sonic, was almost totally unaware that he existed. He then killed Sonic by impaling him through the back without warning, which usually in battle, attacking from behind is an act of cowardice.
* During both boss fights, Mephiles hardly attacks on his own without aid, by either summoning shadows, or cloning himself to use as distractions. He uses the shadows in the first boss fight as shields, and increases the number of them when you get too close.
* Also during the boss fights, he waits to attack you until your back is turned.
* He also doesn't fight you directly until you expel him from Shadow's shadow.
* He also managed to convince Silver and Blaze into attempting to kill Sonic before actually doing it himself, which would in turn release Iblis, though there was a much stronger form of Iblis already free in his time while he had a Chaos Emerald at hand.
* After he begins to lose the first boss fight, he promptly flees by opening a portal in time, and altering it before Shadow and Omega can jump through.
* In the time ten years previous to the story that takes place, when Shadow corners the newly created Mephiles before sealing him away, Mephiles' voice sounds startled if not frightened before quickly shifting into his more recognizable tone as he makes a threat to Shadow.
Mephiles also seems to have a habit of waving his hands when he speaks, as he's seen doing so in nearly all of his appearances, ranging from holding his hands up high while making a declaration, to holding them out to the sides slightly or even in front of himself while making himself appear as an ally to Silver and Blaze.
Mephiles also showed limited interest in people, taking particular interest in Shadow, Omega, Silver and Sonic, the latter only because he needed to kill him. Mephiles is shown to hold a particular hate for Shadow since it was he who sealed him in the Scepter of Darkness. This being said, Mephiles did not acknowledge Rouge, Blaze or Elise, whom he would have been aware of, while the rest of the game's cast did not know of him just as much as he did them.
A comparison between Mephiles and Shadow.
Abilities
Mephiles can manipulate and move through time with an ability similar to Chaos Control. His primary offensive technique is a massive sphere of black energy that is spawned from his hands that home in on their targets. He can also use the energy spheres to move himself and others through time. Furthermore, he can alter his physical form to sink into the ground and merge with the shadow of another. He can also manipulate shadows to create "clones" of himself, although they are warped and imperfect without the power of the Chaos Emeralds. He can also merge the clones together to make large shadow monsters. With two Emeralds, he can create an army of perfect clones. As seen in "The Showdown with Mephiles" cutscene, Mephiles can also knock opponents away by firing shockwaves of energy at them. Mephiles's final attack used before transforming into his Solaris form was a long energy bolt (dubbed the "Dark Chaos Lance" by fans) that he extends from his right hand to impale Sonic.
Mephiles impaling Sonic in Sonic the Hedgehog (2006)
Mephiles appears to be immortal, surviving every fight he takes part in, and whenever he is beaten he seems to just shift into his ooze-like form. Whether or not he is capable of feeling pain is unknown; though he reacts to taking damage during his boss battles with Shadow, he merely stood and allowed himself to be shot multiple times when confronting Omega at Wave Ocean.
Mephiles' Ooze-like form.
Mephiles is also a highly skilled manipulator, as he was able to easily manipulate Silver and Blaze to nearly get his desired result.
Mephiles has also demonstrated the curious ability to, with one Chaos Emerald in his possession, warp the other six Emeralds to his location instantly, which he did after the Flames of Disaster were released from Elise and before reuniting with Iblis.
He is also shown to have adept knowledge on using modern technology, as evidenced by his knowing exactly which files in Dr. Eggman's computer to use when trying to persuade Silver to assassinate Sonic the Hedgehog. This is most likely due to his apparently endless lifespan and time travel power allowing him to study the world around him for as long as he needs to.
That's all the information I can find on Mephiles. Here you may feel free to discuss about Mephiles the Dark.