Google an image of a flame angelHow does he look sick? He's very light in color.
Google an image of a flame angel
garlic will help rid the fish of any disease
I actually think this might be a Hypomelanistic solar flare angel that I recall seeing some years ago. Still looks a tad pale (though hypomelanistic Angels lack pigments, so may be normal for this one). You could try some foods with beta carotenes in them to see if color can be restored. So, perhaps a few jumped assumptionsNice score indeed if it is a solar flare.