When John Milton names and describes the worst of the fallen angels, he tells us where in the Mediterranean world and the Levant they set themselves up as false gods to be adored. The closer to Sion, the worse you are. So in that sense Moloch, whom he names first, is, after Satan and Beelzebub, the worst of all.
It's bad enough that he was worshipped by the nearby Ammonites:
Nor content
With such audacious neighborhood, he caused
The wisest heart of Solomon to build
His temple right against the temple of God
On that opprobrious hill; and made his grove
The pleasant valley of Hinnom, Tophet thence
And black Gehenna called, the type of Hell.
