I figured I'd make a decent build for fresh 70's farming DB's as they gear up. This build isn't cooldown dependent or resource dependent which is great for players who just joined the 70's club. Your main damage dealer is essence free. You just need corpses to do damage. I don't recommend doing T10 and up with this build. The gear just doesn't have the damage for it. Works just fine in T9. It's not really meant for speed, but it's fairly quick for T8. Like most players when they get full sets and full ancients, they will be farming T10 or T13 so Sage builds won't really be needed. Until then, this will suffice.
This is a quick 'n' dirty guide, but not to worry. I'll finish up the details later.
I know there are questions such as why Dead Cold rune for Corpse Explosion. Answer: Because Dead Cold procs Krysbin's Sentence and you will be spamming Corpse Explosion all over the place.