Considering how young he looks, Marluxia is about 21 years old, give or take a few years.
Around his twenties.
It has never been said who Marluxia's somebody is.
Vexen was killed frist by axel who was orderd by marluxia
Under Marluxia's order, Axel came to Twilight Town's replica world and stabbed and defeated Vexen after Vexen disobeyed proper orders. Axel wasn't on Marluxia's side, but he needed to gain Marluxia's trust to succesfully prevent Marluxia's eventual betrayal of the Organization.
They say that it's LUMARIA because it's the scientific name of the flower where they took Marluxia's concept
*SLIGHT SPOILER*Axel killed Vexen because he was ordered to do so by Marluxia. Axel accepted Marluxia's order because he needed Marluxia's trust in order to do away with the traitors. Larxene and Marluxia were planning to overthrow the organization, and Axel needed a way to gain their trust and effectively trick them.
Xemnes decided to appoint Marluxia the head of Castle Oblivion when Saix informed him of Marluxia's plan to overthrow the Organization. Saix was unsure of most of the Organization members' intentions and decided to send them off to Castle Oblivion.
Vexen disobeyed Marluxia and personally crafted the Twilight Town memory card and a replica Twilight Town to reveal Marluxia's plan to Sora, because he always felt tension between the aboveground/underground members of Castle Oblivion. Consequently, Marluxia ordered Axel to eliminate Vexen when Marluxia found out.
Marluxia is #11 in organization 13, he weilds a scythe, his element is flowers, and he is the final boss in kingdom hearts(re)chain of memories.
That wholly depends on you. It could be anything from Flaming Flowers to FireWeed.Note: Axel and Marluxia are NOT a canon or in game couple. Nomura has stated there are no In-game pairings.
Marluxia was only stronger than the rest of the Castle Oblivion residents of the organization, so Marluxia isn't stronger than all the other members. He was only stronger than a little over half of the members. He was seen as a threat by Xemnas and Saix and was sent to Castle Oblivion under the secret supervision of Axel. Little did Marluxia know that he was meant to be killed by Sora.
The nobody known as Marluxia has not had his real name revealed in the Kingdom Hearts series. It is currently unknown if the creator of Kingdom Hearts, Tetsuya Nomura, will ever release the real names of Demyx, Luxord, Marluxia, and Larxene.Although many fans of the series have made guesses as to Marluxia's true name, none have been confirmed. The most popular fan-made name is Lumaria, Which happens to be a part of the Latin name for the Roundleaf Hawthorne: Crataegus lumaria.