Angel here would be an "aligned" AI: an AI whose behavior is in line with human values. A demon is simply an unaligned one.
The key point would be that it needs not be actively hostile to human values, but indifferent to them. Think of a Lovecraftian Elder God, not AI Hitler.
The supporting hypotheses would be that it's much easier to create an unaligned AI than an aligned one, as an aligned one is an unaligned one with additional constraints, and that unaligned AIs will wreak massive destruction.
The key point would be that it needs not be actively hostile to human values, but indifferent to them. Think of a Lovecraftian Elder God, not AI Hitler.
The supporting hypotheses would be that it's much easier to create an unaligned AI than an aligned one, as an aligned one is an unaligned one with additional constraints, and that unaligned AIs will wreak massive destruction.