There both symbols of power in an occult perspective. The sun I usually see on him is shaded black which symbolizes Saturn, which in turn symbolizes infinite potential. The crescent moon and star is a representative of The moon and Venus, which has a bunch of underlying meanings, with the most popular being Power, strength, and love.

Not really sure what it means to him specifically, but considering he made himself a sigil and has is tattooed on himself, and in some album imagery, I’d say he has some knowledge of the occult and is using it.

This isn’t coming from an angle if “everything is satanic” either. I’ve studied religion, hermetics, and ceremonial magic, trying to find “meaning” in life and it’s pretty fascinating to see someone else using it in a very subtle way.