i have fire sunder and physical sunder in invertory. 1 point into defiler is all you need because with gear the charged damage percent is like 50-55 percent. You can use 2x defiler and bind demon to clear certain areas like chaos sanc during terrorzones for faster clear, or extremly high poulation pack areas like talrasha tombs tz. Ye im lvl 97 so me maxing out 5 skills and 1 point in rancor means i would finish at lvl 95 for the build. Demonic mastery still buffs tainted damage. They just nerfed the sernergy of blood boil to tainted from 30 percent per lvl down to 20.
i maxed blood boil, summon tainted,demonic mastery, bind demon, blood oath. 1 point into rancor.