I might seem really stupid here, but...

[playlifeloud67]

I did an anagram post a while back, and since then, anagrams have been my  hobby. I anagrammed my character's name (Melody) just because I was curious. I came up with a lot. One was Lodyme. In case you don't see where I'm going with this, I'll be helpful and bold here.

Lodyme.
Dyme + X =  Demyx.

I think I figured out where Demyx's name came from. :O