Culex

"I am matter... I am antimatter... I can see your past... I can see your future... I consume time... And I will consume you!"

- Culex

Culex is an optional hidden boss who appears in Super Mario RPG: Legend of the Seven Stars. Alongside the Crystals, Culex is an even more powerful boss than the main story's antagonist, Smithy, as he has 4,096 HP, the second most of any encounter in the game (behind only Smithy's second phase). Culex, combined with the Crystals has 12,396 HP, which exceeds both of Smithy's phases combined.

Culex himself is an allusion to, as Super Mario RPG: Legend of the Seven Stars is developed by Squaresoft, creators of the Final Fantasy series. Culex has two different sets of game sprites, one for the overworld and a much larger one for battle, resembling the enemy design in the 2D Final Fantasy titles, and these sprites do not have as complex animations and frames, reminiscent of early Final Fantasy games; these features are discrepancies to most other Super Mario RPG: Legend of the Seven Stars enemies. The four Crystals used by Culex in battle are also based on the crystals that appear in the original  game. This connection is heightened by the Japanese name of the Quartz Charm, which is the Crystal Charm. Moreover, the three music tracks associated with Culex are rearrangements of three music tracks from the Final Fantasy series. His battle music is a rearrangement of the boss battle theme from  (initially Final Fantasy II in North America), the music that plays when he is defeated is a rearrangement of the victory music present throughout the Final Fantasy series, and the ending conversation is a cover of the Final Fantasy "Prelude".

History
Culex resides in a cross-dimensional region found behind a sealed door in Monstro Town. According to one of his neighbors, a Piranha Plant, Culex is "always mumbling about Crystal-this and an Evil-that." The sealed door that leads to Culex requires a Shiny Stone, mentioned by the Piranha Plant. When Mario enters the region, Culex greets him and explains his story. He then challenges Mario to a battle, which the player can either accept or refuse.

In battle, Culex is aided by four Crystals – the Earth Crystal, the Fire Crystal, the Water Crystal, and the Wind Crystal. These Crstyals have magical attacks that correspond with their elemental power. All four Crystals can be defeated independently before targeting Culex, but if Culex falls, any remaining Crystals shatter one by one on their next turn.

If Mario's party wins, Culex rewards Mario with the Quartz Charm. Culex then leaves Mario's dimension as Mario is transported back to Monstro Town. The door to Culex also vanishes, leaving a solid rock wall in its place.

At Bowser's Keep, one of the questions Dr. Topper can ask when he quizzes Mario is what Jinx, Goomba, and Culex have in common. The correct answer is: "They live in Monstro Town."

Regional differences
Culex's alignment and motives differ drastically between the Japanese and English versions. In the Japanese version, Culex claims to be a timeless overlord made of pure evil. As a two-dimensional being, he is perplexed by the three-dimensional forms of Mario's party, so he demands a fight to try and understand them. Upon defeat, he recognizes the party's strength and positive energy, and he and his pocket dimension disappear until the day he finally gains the solidity of the third dimension. In the English version, Culex's dialogue and backstory are completely rewritten: he is said to be a "Dark Knight of Vanda" sent by the Dark Mage. He has nobler mannerisms, and attempts to leave Mario's company on good terms.

Quotes

 * For a full list of quotes, see here


 * "Greetings. I am Culex, Dark Knight of Vanda. I've crossed into this dimension to fight for the Dark Mage. But this world is uninhabitable for me and my kind. I must return to my own world. Before I go, though, I would like to challenge your strongest knight. Will you accept my challenge? You will enter combat against me?"
 * "You are wise to hesitate. Without any weapon or armor, you have no chance."
 * "En garde!"
 * "I am matter... I am antimatter... I can see your past... I can see your future... I consume time... And I will consume you!"
 * "A little off, eh?"
 * "Perhaps in another time, another game, we may have been mortal enemies... Let us part as comrades in arms."
 * "Take this. Treasure it as a keepsake of our fight."
 * "Farewell, champion knight!"