Devil isn't a creature per say, but a title. The Devil that people usually refer to is Lucifer, who is also referred to as Satan. But in some lore Lucifer and Satan are considered to be two separate beings. Beelzebub has also been attributed to the Devil title.
Samael is also an archangel that left heaven in the same time as Lucifer, yet he is not known as the Devil or even a devil, most people don't even know him as being an archangel.
No, nothing is more dangerous than the devil. The devil is the ultimate source of evil.
nothing
nothing is
No.
There are many places where one can find more information about devil dogs. One can find more information about devil dogs at popular on the web sources such as Drake's Devil Dogs and The Pioneer Woman.
nothing
There is no Dahak!
Hades is a 'place', another word for hell, the devil is an 'entity'
No!
The only thing more dangerous than the devil would be the God of Judaism, Christianity, and Islam. Dahak is a pretend god who does not exist.
No.
Nothing. Nothing is mightier than god,nor more evil than the devil. If you eat nothing you die, and dead people drink nothing.