What does 'Hyoma' mean?
I see a friend of mine using the word 'Hyoma' (in Romaji) to describe some kind of devil, yet no matter how I translate it or even translate words similar, I can't even come close to it, am I missing something?

It means devil of ice, may be. ^^

氷魔

Here is an example: http://dic.pixiv.net/a/%E6%B0%B7%E9%AD%94

Maybe he refers to the character in the Metal Saga.