Epsilon

"I will not run from this fight. For I know that this bridge must be crossed to achieve our ideal. They will tremble before the power of Epsilon!"

- Epsilon

Epsilon, known as Ipsilon (イプシロン) in Japan, is the "Unknown Energy Manipulator: Test Model" from Mega Man X: Command Mission. He serves as the leader of the Rebellion Army and acts as the game's antagonist up until the final chapter.

History
Epsilon masterminded the revolt on Gigantis Island and is the leader of the Rebellion Forces. A proud individual, he is often seen standing silently, his stoic and quiet nature creating a strong presence. Epsilon was the only Reploid to survive the Supra-Force Metal infusion experiments, giving him heightened intelligence and strength capabilities. All other volunteers in the experiment either went mad (Maverick) or perished outright. Though Epsilon retained his sanity, he realized he could try to reproduce the same results that he had on other Reploids, and thus staged a revolt for Reploid Freedom, believing that Reploids could evolve past what humans had made them to be, and become more advanced.

He led the Rebellion with great charisma and leadership, so much that Scarface and Ferham were willing to put their lives at stake for him. He even showed the intelligence to keep the two of them as his main hands, as even Botos seemed to hold a bit less of his trust in comparison. His body also still contains a sizable chunk of Supra Force Metal from the experiments, hidden underneath his black torn cloak which is reminiscent of X6's Sigma (the rods on his shoulders are also reminiscent of the X7 Professor Sigma). Epsilon's name and motif share similarities with Sigma in general, as both are large, skilled, visionary Reploids named after a letter of the Greek alphabet.

Throughout the game, Epsilon makes attempts to control Giga City's resources while crushing the Resistance that opposes him. Realizing he needs force to make others listen to his ideals, he resorts to creating a missile armed with Supra-Force Metal to keep his foes at bay. Eventually, X and his team make their way into his fortress to confront him. After Scarface falls in his name, Epsilon takes them on himself only to lose. He then stated that his motivations for creating the Supraforce metal was to have the power to ensure a Reploid-only nation was created, as they were left with no other options due to the Federation branding them as Mavericks. As he tries to continue fighting, X brings him down with his buster.

After the end of the game, Epsilon was deferred of all Maverick charges posthumously, most likely due to the restraint he showed in not killing any innocents during his activities (having banished the humans from Giga City without harm, simply forbidding them to return) and the fact that his whole Maverick status came about as a result of Redips' manipulation of events.

Round 2
As a result of Supra-Force Metal testing, Epsilon is extraordinarily strong and durable, as it took six Reploids to take him down. Using his implanted Supra-Force Metal grants him even more devastating attacks, as well as alternating resistance to Combat and Shot attacks and regeneration capabilities until his Supra-Force Metal output has been weakened by damage. Epsilon's second phase is called Eject Epsilon, having his restraints removed and his Supra-Force Metal output slightly boosted.

Grave Ruins Base
(Maverick Hunters X and Zero make it to the top on the Grave Ruins Base and run in to confront the Rebellion Army's leader, Epsilon.)

Zero: Hah! Epsilon.

X: It's game over! For your plans, and your Rebellion!

(Epsilon stands, towering over the two Hunters.)

Epsilon: So, the Maverick Hunters have arrived. If you think you've declawed us by securing the missile's Force Metal, you're terribly wrong!

Zero: What?!

(Epsilon hold his left hand against his chest.)

Epsilon: We still have Supra-Force Metal here! After we dispose of you, we'll use it in the warhead!

(X begins charging up.)

X: I don't think so. Not if we have anything to say about it!

(X fires a fully charged blast, but at the last second, Scarface leaps in the way and absorbs the blast.)

Epsilon: Scarface!

Scarface: Commander, please leave this to me. That rat, X... he learns new powers as he fights. If you were to somehow lose this fight, where would we be then?!

Epsilon: Out of the way, Scarface! Or are you suggesting I would lose?

Scarface: You alone carry the Rebellion Army torch! Commander Epsilon, you are the embodiment of our beliefs! Make the choice to live another day!

Zero: We won't let you get away, Epsilon! Your fun and games have come to an end!

(Scarface turns to face the Hunters again.)

Scarface: I beseech you, Commander... Allow me to demonstrate the depth of my faith!

(Scarface proceeds to battle with the Hunters again, only to lose a second time.)

(In his last breath Scarface raises his arm in honor for the Rebellion Army.)

Scarface: Glory to the Rebellion!

(Scarface coughs one last time before exploding. Epsilon looks down upon his fallen bodyguard, then glares at the Hunters.)

Epsilon: I can see you are determined. But Scarface... I will not run from this fight. For I know that this bridge must be crossed to achieve our ideal.

(Epsilon steps forward in a battle stance.)

Epsilon: They will tremble before the power of... Epsilon!

(The Hunters engage Epsilon in battle.)

(After the battle, Epsilon crouches near the ground, terribly wounded. X continues to keep his Buster trained on him.)

X: Why?! Why create something as dangerous as the Supra-Force Metal missile?!

Epsilon: For power. Without power... our ideas will be ignored.

X: What?! There must be a better way...

Epsilon: The Federation has labeled us Maverick. What other options do we have?!

(Epsilon climbs to his feet.)

Epsilon: As long as I am in operation, I will...

Zero: Now, X... shoot!!

(X fires his final blast at Epsilon, this time bringing him down for good. X approaches and retrieves the Supra-Force Metal Epsilon had been using.)

X: So this is Epsilon's Supra-Force Metal?

Zero: Despite all their big talk, the Rebellion Army's actions were still Maverick.

Axl: They put the Earth itself at risk.

Zero: We did the right thing.

(From behind, Colonel Redips approaches the group.)

Colonel Redips: I've picked up the vibrations of Supra-Force Metal here.

X: Colonel Redips!

Colonel Redips: What happened to the Metal?

X: Here, Colonel. Epsilon had it, but we retrieved it.

(X hands the chunk over to Redips, who appears to stare at it greedily.)

Colonel Redips: So this is it...

(Colonel Redips straightens up.)

Colonel Redips: You have performed splendidly! You are to be commended, X.

(Colonel Redips salutes X, and X responds in kind.)

X: Thank you, sir.

Colonel Redips: Now men... Return to base! A plane will arrive for you shortly.

Trivia

 * Due to Epsilon having a name based on a letter of the Greek alphabet, being a decoy final boss, and having his voice provided by Dave Petit, many fans have often compared him to Sigma, who follows the same naming convention, was voiced by Petit in Mega Man X8, and was the decoy final boss of that same game.
 * The pronunciation of his Japanese name, Ipushiron, is actually the Greek alphabet "Υ / υ" (ypsilon) pronounced in Portuguese.
 * Coincidentally, he also shares his name with the Sonic the Hedgehog robot E-104 Epsilon.