Elder brother of Mephistopheles, as well as EGO's true form.
Lucifer is the ruthless Great Demon King of Hell, the human version of the underworld, as well as the final foe in the second story arc of the trilogy.
His species is Mewtwo.

When the EGO experiment went awry and demons were summoned, Lucifer felt attracted to human arrogance, and used EGO (the artificial life-form mother computer) as a host to gain a physical form in the human world.

Due to EGO being set to sleep mode, Lucifer wasn't conscious and lacked his true power.
However, even when asleep, he controlled many of the Infernals on Earth, and still possessed deadly psychic powers.

When Luna and Scarlet wanted to shut EGO down for good, they had to awaken EGO from its slumber state, which caused Lucifer to awaken within EGO.

Lucifer explains that he gave humanity freedom because he saw unlimited potential in the humans. Potential that could not be achieved when trapped by the Great Divine Will.

However, as time went on, he started to realize that this experiment was a mistake.
Man started to use religion as an excuse for bloodshed and war, and soon came to abandon the very entities they worshipped, blaming their gods for the countless innocent victims their bloodthirst caused.

Lucifer also notes that mankind always run away from their responsibilities, and always burden innocent people with the consequences of their actions.
According to him, there are but a few people in this world who regulate order, but they're being disregarded as human beings by their own kind, being used as nothing more than tools to clean up the shit most people cause.

But when human affairs summoned demons into their world, and when humans then sent those demons to Luna's innocent world just for the sake of being free from the consequences of their own actions, Lucifer had enough.

Lucifer then gives Luna a proposal.
All it takes to remove the demons from Luna's world is the complete annihilation of the human universe.
Lucifer offers the safety and liberation of Luna's world in exchange for the end of the human world.
He insists that Luna's world shouldn't have to suffer under the humans' incompetence, especially since they're innocent, and that his solution is for the best for everyone.

Scarlet screams that it's a lie, but Lucifer then explain that because he's part angel, he cannot lie in the first place.

Luna's vibes also tells her that Lucifer is speaking the truth, but also wonders if it's right to execute an entire universe merely to guarantee the safety of the innocent...

After some thought, Luna says it's not her right to judge others, especially not when it comes to life and death.

Lucifer is surprised by this statement, and asks if she's really willing to risk the destruction of her own world.
Luna replies that as long as there's hope, she will continue to fight for what's truly right.

Lucifer then loses his patience, and then considers Luna contaminated by humans, so she too must atone for her sins, just like all humans, and Lucifer won't hold anything back to get what he wants.

Lucifer exclaims that there's no hope for mankind, and to demonstrate his true power, he uses his insanely powerful Psystrike to destroy mankind's last bastion of hope and escape: Mars.

Having just obliterated an entire planet, Lucifer then uses his massive Psychic powers to create a black hole with the intention of swallowing the entire universe, as well as setting the stage for the final battle.

Luna then realizes that she has no choice but to call upon the power of Death itself and share her body with Nyx, making her able to stand up against Lucifer.
(She has gotten this power after defeating Death Mephistopheles. She refuses to use such insane power up until now since she thinks no-one should have the absolute power over Death, and out of fear of losing control over such insane power.)

Eventually, Lucifer is defeated, but not dead.
He is then asked which god is real, to which Lucifer replies with an arrogant smile, "Perhaps you should learn to accept your differences than to accept something as your truth," after which he fades into a dark dimension.


Lucifer is shown to be incredibily powerful, but he prefers not to utilize this power unless he deems it absolutely necessary.
However, despite his calm demeanor, he prefers to rule with an iron fist.

Unlike his younger brother, Lucifer is much more calm and gentle, almost like a gentleman.
Also unlike his brother, he appears to have respect towards the Divine and actually acknowledges his brother's existence.
Whereas Mephistpheles relies more on raw physical power, Lucifer prefers magic more.

He believes in justice, but has his own interpretation on what's right and wrong, so he might not always have the right actions for his intentions.

Lucifer is also incredibily wise, and thanks to his incredibly potent Pyschic powers, is omniscient, meaning he knows everything about the things that went on and is going on in every single dimension.
His Psychic powers can hit past immunities, and his Psystrike is powerful enough to destroy an entire planet.
He also can read minds and use telepathy. There's no way you can ever hide anything from him.

Despite that, he is strangely fair. When he feels that someone with a strong ideal challenges his ideal, Lucifer won't destroy his opponent outright.
This is the reason he didn't destroy Luna or the Earth right away, as he wanted to give Luna a chance to prove her ideal's worth.

His title is Great Demon King, and is often refered to as "His Excellency" by other Infernals.

Lucifer's design is largely based on SMT IV's Lucifer, complete with pulsing fetus arm.