This isn't a lecture or paper, just a discussion about Menzies. We know who Dhuum is, we even know who Abaddon is, but Menzies still remains more or less a mystery.
There are three main theories on Menzies, which I will briefly summarize:
1) The God Theory:
Some feel Menzies is a god, like his half-brother Balthazar.
2) The Less Entity Theory:
Some feel Menzies is not a god, but rather, a lesser entity like the Mursaat or Seers who has ambitions of godhood by usurping power from his half-brother Balthazar.
3) The Abaddhuumenzies Theory:
Some feel that the names "Abaddon", "Dhuum", and "Menzies" all refer to the same outcasted sixth god of the pantheon.
Until recently, a stumbling block in the way of Menzies status as a god was the fact that he is called the "Lord" of Destruction, rather than the "God" of Destruction. However, in the new Nightfall Manuscripts, the gods are refered to as the Lords and Ladies of their respected spheres, rather than the old form of gods. This seems to suggest that Menzies may indeed be a god, but is not confirmed.