Ah that makes sense. But I don't think the cover of the death note really matters
no it doesn't its just cooler XD
Also, Angelo is safe because of this rule:
If a Death Note is owned in the human world against the god of death's will, that god of death is permitted to stay in the human world in order to retrieve it.
In that case, if there are other Death Note in the human world, the gods of death are not allowed to reveal to humans that Death Note owner or its location.