Not to mention Glorious Exultation of Xotli, if you really care about min-maxing BtD.
Avatar-General sounds like a really uphill battle. If all you care about is BtD, why bother finishing Avatar? What about stopping at Flame of Xotli (Avatar) and Tome of Erlik (General)? Then you can go all the way up to Knowledge of the Underworld in Possession, and all that +magic improves the BtD DoT. Something like this:
http://goo.gl/HBb2Nj Then go for Prince of Terror for your gold AA.
Not saying that's the best PVP build, but I think it min-maxes BtD and gives you some survivability too.