Goldfire is a unique power to the Seraphim Twins, which involves summoning and controlling concentrated blasts of a bright yellow plasma.
Goldfire is usually seen being used a massive beam, or engulfing the user in the burning plasma (This can often severely injure or kill the user).
Oddly for a plasma based attack, Goldfire is not bright enough to blind those who look at it, only being slightly brighter then typical fire.
Goldfire is known to be EXTREMELY hot, though its heat is very localized, and does not often spread. It can easily burn holes through titanium and other similar metals.
The Seraphim twins are rarely seen using it, due to its extremely dangerous and volatile nature.