Er..The corruption is definitely from Abaddon/Dhuum. For the most part it seems to be Abaddon as Dhuum only has forces, while Abaddon still has a form and power.
Dhuum just seems kind of..bodiless or at the very least concealing his physical form by all means. Abaddon seems a bit arrogant, and doesn't fear showing off his physical form.
A look at "Arachnia"
Gmr Leon