I understand if you get confused with Marluxia when he was a sprite. But honestly, no woman unless taking a huge amount of steroids will reach the body Marluxia has once Re: CoM came along. Buff as hell, and deep voice. People associate pink with females too much, when in the past, it was more of a male's color. Yes, a male's color. And in some countries it still is, or it fits both sex. Japan happens to be one of them. I already broke the stereotype when I learned this.
For the topic, I would rightly say that:
Flowers = Element
Death = Theme
In other words, there's no doubt that his element is Flower. It's practically in official writing. But in the same way that Demyx has music as his theme, and Luxord with his casino, Marluxia's happens to be tied to death, and it's greatly symbolized in the sakura petals when it comes to the Japanese. It's even more obvious once you take his scythe, the Death Counter he uses, and the black cloak. He's basically an image of the Grim Reaper.
Except he's more pretty looking and not a skeleton :3.
I think I'm the only one who practically laughed at that when it came on my screen.