Mephiles

Mephiles the Dark (pronounced [mɛfɨləs] or [mə'fɪliːz] in English) was a character and was one part of the being that was the primary antagonist from Sonic the Hedgehog.
Mephiles has three forms; the first and original was a dark, blackish-purple formless ooze or gas with some gaseous qualities. In his second form, Mephiles appears almost identical to Shadow the Hedgehog, aside from having green eyes with slit pupils, no visible mouth, and the fact that everything that is red on Shadow is a pale powder blue on him. His third form (and his preferred one when he uses his abilities) was a crystalline, anthropomorphic hedgehog form resembling the appearance of other hedgehogs in the Sonic series, such as Sonic himself; in this form, he has no visible nose, mouth, or feet. His name was based on the one of the names of Mephistopheles related to the legend of Faust.
Mephiles was accidentally created during the Solaris Project, under the supervision of the Duke of Soleanna. He was actually an extension of Solaris himself; his conscious part. He 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 present, Dr. Eggman accidentally releases him while trying to steal the scepter from Shadow and Rouge, and runs away scared, not even bothering to send his robots to attack him. Mephiles then transformed into a copy of Shadow via absorbing his shadow, and sends Shadow and Rouge into the future after he realizes that Shadow doesn't know who he is. He seeks to get the Chaos Emeralds and bring pain and despair to Princess Elise, with the goals of making her cry, therefore releasing the "Flames of Disaster" (a.k.a. Iblis) and then fusing with him, to reunite them both as a single entity, Solaris.
To accomplish this, he tells 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 sends the two back in time, making them believe that killing Sonic would save the 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, where Mephiles is shown to hold a particular hate for Shadow since it was he who sealed him in the Scepter of Darkness. 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 attempts 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), attempting 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 takes the upper-hand, Mephiles knocks him into a wall with an energy blast and incapacitates him when he lowers his guard, but Omega intervenes and drives Mephiles off. Later, Omega meets Mephiles again, who reveals to Omega that he was one that would imprison Shadow in the future, leading to the robot shooting him up 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).
He, along with Omega and Rouge, later meet him again. Again, Mephiles offers Shadow a chance to join him, but Shadow, knowing Mephiles' true intentions, flat-out refused the offer. Mephiles is fought again (he's the final boss in Shadow's story), and loses. After his seeming defeat, however, Mephies proves 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. It is also revealed in the Last Story that his lie to Silver and Blaze about Sonic being the Iblis Trigger was actually a half-truth: 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 history.
Mephiles the Dark is unique among a majority of the villains in the Sonic series. Unlike most of them, which are driven by a lust for power and control (or in Shadow, Chaos. and/or Gerald Robotnik's case, vengeance), Mephiles (as Shadow put it) only seems to crave destruction. He is portrayed as a cold, ruthless villain with no sense of compassion whatsoever. 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. 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. Aside from his failed attempt at convincing Shadow to join him, Mephiles' manipulation tactics often work, which is why he came so close to succeeding with his plot to destroy the world.
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 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 doesn't wait to attack you head on 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, though this may have been because he lacks a mouth and this was to either direct attention away from that or to make his expressions a little more readable. This may also be because he liked to present himself assertively, and doing so showed confidence.
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.
This being said, Mephiles did not acknowledge Rouge, Blaze or Elise, whom he would have been are of, while the rest of the game's cast did not know of him just as much as he did them.
He also seems to lack any interest in girls, as the three that did cross his path, he either did not refer to them, did not answer them, or just flat out ignored them. It's odd, since Blaze had stood near him when he sent her and Silver into the past (Though he might have purposely dropped her off in the middle of the ocean after he realized that she recognized Sonic.), and Rouge was there when he was released and there at Dusty Desert (She probably wasn't as significant to him as Shadow and Omega), and Elise was the whole reason he needed to kill Sonic (Though he was only interested in freeing Iblis). Of course, the only interest he even has is the pain of others (His main goal being the destruction of time itself).
AbilitiesMephiles 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. Furthermore, he can alter his physical form to sink into the ground and merge with the shadow of another. He can create "clones" of himself, although they are warped and imperfect without the power of the Chaos Emeralds. With two Emeralds, he can create an army of clones. 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 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 is also a highly skilled manipulator, as he was able to effortlessly manipulate eleven people (Sonic, Tails, Knuckles, Amy, Shadow, Rouge, Omega, Silver, Blaze, Eggman, and Elise) over a time period of 110 years (ranging from the failure of the Solaris Project to Silver's post-apocalyptic future) in order to get a single result in the present.
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.