Do you deny Satan and his demons still sin? Or do you deny their existence at all?
They sin now.
Hell, the law of fire, was created for them ... and not “for them” in the sense that it’s something they would want.
I’m not denying their existence at all.
Just pointing out that they will not be reigning in Hell ... God will be.
And if sinning is to be entirely done away with, so that none of the works of the Devil persist (Hell being God’s work), that means that those monsters, who knowingly rebelled from a holy state in His presence, will face the most sever wrath of all. And justly so.
There is, after all, a difference between wanting and having.