Personally I don't like it, it looks like an ugly version of the national socialist flag.
Besides, if Joy of Satan is not a political faction, then it does not need a flag, since it already has its own logo.
However, since we are national socialists, surely we would have flags of our nation, or our future Empire in our homes or places of worship.
But no matter how much influence JoS may have on the governments of the world in the future, or even if JoS members themselves will head a government, Joy of Satan and government remain two separate things.
So if it comes to flags, I think it's better to create one for this Empire to come. In my opinion it should have the colours white, black and red (like Egypt's), it should have some gold decorations, and it should remind of royalty, nobility and strength.