Mr. L

"The Green Thunder strikes like lightning!"

- Mr. L

Mr. L, also known as The Green Thunder, is Luigi's villainous, hypnotized alter-ego. He has appeared only in Super Paper Mario.

In the Light and Dark Prognosticuses
It is implied several times that Mr. L/Luigi is the "man in green" referenced in both the Light Prognosticus and the Dark Prognosticus, both of which state that this man in green and his affiliations will determine which prophecy is true. As such, it can be taken that, if Luigi were to have stayed Mr. L throughout the course of the game, the Dark Prognosticus would have been fulfilled and all worlds would be destroyed, making the end of Luigi's hypnotizing and evil ways integral to Super Paper Mario. Dimentio additionally stated that the Dark Prognosticus mentions Luigi as the ideal host for the Chaos Heart.

Early History (as Luigi)
Having been warped to Castle Bleck alongside the Koopa Troop, an unconscious Luigi (who had not yet become Mr. L) was among the audience of Bowser and Princess Peach's wedding in the castle's wedding hall. As Luigi gained consciousness during this forced marriage, he attempted at saving Peach from the clutches of Count Bleck and associates, but ended up only provoking the Chaos Heart (which was secured by an escaping Count Bleck shortly after) and was seemingly sent off to another corridor of the castle.

After Chapter 2 was beaten, players took control of this dazed Luigi who had just gained consciousness in Castle Bleck's dark innards. Being manipulated by a pair of Goombas (one of which was Gary), Luigi attempted at saving his group and Peach, but ended up coming to a dead end, where he was promptly surrounded by Nastasia's forces (as well as his two Goomba "friends," who also joined Count Bleck's Army, one by will and the other through hypnosis). Though Luigi's fate was not explicitly given, he was shown to be tackled by the troopers and was seemingly about to be hypnotized by Nastasia (foreshadowing Mr. L) just as the scene cut.

Encounters with the Heroes and Other In-Game Events
Mr. L himself was first seen in the Whoa Zone, where he attacked Squirps in a chamber shortly before the statue of Squirpina XIV and the resting place of Outer Space's Pure Heart. After quickly trash-talking the Four Heroes, he engaged in a brief mini-boss battle with them. After his forty HP were depleted, Mr. L fell to the ground and complimented the heroes on their battle skills, but quickly summoned his mechanical battlesuit Brobot to finish them off. With the effect of the screen ripping in half, the characters were all transported to the depths of space, where Mr. L and Brobot battled them above what flipping would reveal to be a green, mountainous expanse. Using Squirps's gun, the heroes knocked Mr. L out of the skies and landed him on the Whoa Zone's grounds once more. With one last boast of a future ability to prevail over the heroes, Mr. L escaped, allowing them to secure the Pure Heart.

Mr. L would next appear in the Castle Bleck meeting intermission after Chapter 4, the beginning of which focused on his "new-minion orientation." Mr. L was here shown to be boastful even around fellow minions of Count Bleck, seeing his comrades as weaklings and "junior minions." O'Chunks and Mimi reacted negatively to this, with Mimi noting to Mr. L that he too, had been, defeated; Mr. L's response was that he was "merely scouting" Mario and would soon defeat him. With a cry of "L-ater!", Mr. L jumped off to Castle Bleck's unseen repair bay as Count Bleck quoted a Dark Prognosticus section stating the potential of the man in green.

In the intermission after King Croacus's defeat, Mr. L expressed a longing to make another attempt at destroying the heroes with his newly-repaired Brobot. However, Nastasia relayed a command from Count Bleck for the minions not to attack, and Mr. L thus could not carry out his plans. Dimentio, however, encouraging the fulfillment of his own gambit, soon had Mr. L and the other minions off to attack in saying that Count Bleck would be pleased if they were to end Mario and Peach's games.

As laid out, Mr. L would next appear in the destroyed form of Sammer's Kingdom, where he took the stone Pure Heart of Sammer's Kingdom for himself and, with the help of his improved Brobot, engaged in battle with the Mario and Peach once more. He, of course, lost this battle to the heroes, and his confidence was greatly wounded as he ran away, leaving the broken Pure Heart for the group of heroes to take.

After Mario's team left the World of Nothing, Mr. L was shown in a cutscene where he pondered his inability to beat the heroes to himself. Shortly afterward, he was confronted by Dimentio, who attempted to destroy him on the apparent basis that he, having lost once more, would be unable to show his face to Count Bleck. (In actuality, Dimentio had planned to undo Mr. L's hypnotism and reunite Luigi with Mario so they could help him destroy Count Bleck; he also later used his ambiguous help to Mario as a basis to convince him to join him in the battle against Bleck.) Dimentio successfully Game Overed Mr. L, sending him to The Underwhere.

Super Dimentio
In destroying him, Dimentio cured Mr. L of Nastasia's hypnosis and reunited him with Mario, and standard Luigi joined the soon-to-be-complete Heroes of Light. (Of note is that Mr. L's theme song accompanied Luigi's cowering in The Underwhere as he first joined the Four Heroes.) The Luigi of the Light Prognosticus continued to fight alongside Mario, Princess Peach, and Bowser, who were eventually able to defeat Count Bleck. However, prior to this momentous victory, Dimentio had planted a Floro Sprout seed in Luigi's mind that grew into an adult Sprout just as he was ready to finish the remaining three heroes off so he could destroy all worlds and create his new ones. Though Luigi noticed and resisted his brainwashing, his fate was imminent: Just as Nastasia once had, Dimentio had created Mr. L.

Making way for a new creation, Dimentio ordered Mr. L to move into position and soon merged him with the Chaos Heart in a purplish-black hole resembling the Void. When one with the evil heart, Mr. L became the more Dimentio-themed Super Dimentio, a gigantic clown-like puppet bearing some resemblance to a twisted Luigi. Seemingly eliminating the new Mr. L's sentience, Dimentio took control of Super Dimentio, challenging the remaining Heroes of Light. With help from Count Bleck and his minions, the heroes were able to summon the Pure Hearts to destroy Dimentio and the Chaos Heart, bringing back Luigi and apparently finally erasing his hypnosis and brainwash.

Super Smash Bros. Brawl
Mr. L's only appearance beside his large role in Super Paper Mario is a passing mention (under the name Mister L) in Paper Luigi's trophy in Super Smash Bros. Brawl. This one-sentence mention states that Luigi only has a rumored "close relationship" to Mr. L and misattributes Luigi's brainwashing to Count Bleck.

Personality
A gentleman thief, Mr. L is very cocky and overconfident, a stark contrast to the chicken-hearted, reluctant Luigi. He thinks highly of himself and is not slow to reveal it, often trying to openly annoy other in-game characters. He has a sophomoric belief in his often-boasted-of abilities, as he is very shocked at his failures as their series begins. He is very daring, and as such reveals an attraction to Princess Peach and jealousy of Mario's jumping ability. His loyalty to Count Bleck, while very deep (with him greatly longing to impress the count), is never explained, and he seems to care little about the expenses worlds would pay had Bleck's plans realized.

Mr. L has two catchphrases: "L-ater," which he continuously proclaims when exiting Castle Bleck, and "Have at you!", his battle cry. He has become well-known for his introduction (actually done only once in the game, not counting a shortened version featured in his new-minion orientation), in which he is given a repeated, blurring closeup as he spins around and strikes a pose, shouting "MR. L!" as rotating green rays are emitted from his body. He also has a knack for nicknaming, referring to Mario as "Mr. Jumpsallthetime," Peach as "Ms. Alwaysgetskidnapped," or Bowser as "Mr. Getsfoiledallthetimebytheredguywiththemoustache" during their first confrontation.

Dimentio's Mr. L seems to have no personality differences from Luigi, if he can be said to have any personality at all. Super Dimentio, however, does give a few Mr. L-esque cries, such as "GREEEEEEN!" and "L-POWER!".

Physical Appearance
Mr. L strongly resembles Luigi, though dressed in a black jumpsuit that strangely retains his former overalls' large buttons. He also wears a green scarf around his neck and has a new cap with a black background and reversed "L." Over his face is a small, black mask which seems to effectively hide his identity; this mask makes his eyes and eyebrows appear white. His gloves are dark gray and his shoes are black, and Mr. L, unlike standard Luigi, is shown to have a belt.

It may also be worthy of note that official artwork depicts Mr. L's mustache as black whereas Luigi's Super Paper Mario artwork gives him a brown mustache. In game, however, both forms' mustaches are brown.

While it is somewhat obvious that Mr. L is a brainwashed Luigi to the Player, the other characters in Super Paper Mario don't make the connection, though they do feel like they know him in some way. This is done for both comic relief, and to facilitate the game's developing storylines.

Powers and Abilities
Mr. L's abilities are largely the same as those of Luigi. He runs and jumps around not unlike a playable character and can also Super Jump, a trademark move of Luigi's in Super Paper Mario. Also hero-like is his unique ability to occasionally revive his health with an endless supply of Shroom Shakes.

However, Mr. L has some prowess that Luigi does not, namely his inventiveness. Though Luigi has been known to have run a mechanical-themed board in the Mario Party series, his mechanical prowess has not been consistently shown to match that of Mr. L. As aforementioned, Mr. L builds, upgrades, and pilots his own Brobot mech throughout the course of Super Paper Mario, pioneering the art he refers to as brobotics.

Trivia

 * According to The InterNed, Mr. L's theme song is titled "Mr. L, Green Thunder."
 * Mr. L's nickname of "The Green Thunder" may come from Luigi's Thunderhand ability from Mario & Luigi: Superstar Saga, but this is unconfirmed.