Coming back around to Ishar, I wonder if he was the one who bound Ba-Edo-Mishram. It's in the name kinda, Melishi~Ishar. Plus Melishi seemed to have abilities that were unexpected for a bondsmith. Several of the heralds were present at the binding, including at least Kalek and Nale. Maybe they weren't completely insane yet and were trying to help fight the false desolation.
As for T-Odium, going back to Renarin's vision in RoW and interpreting it in the light of Taravangian's ascension leads me to believe that T-Odium will try for a stalemate in the contest of champions, that way there can be no end to the war. Permawar seems to align well with Odium's intent, and it would mean the preservation of humanity on some level which is what Taravangian wanted.