Here we are again... new Path of Exile game and Detonate Dead is good again.
This build has been growing in popularity as people realize how TANKY Blood Mage can get while utilizing its ascendancy and Grim Feast to have a very large ES/Life pool. This build also has high single target damage and excels in breach/ritual.
My friend Jacob has been playing this and suggested it to me and I was going to play it in Hardcore but unfortunately died before getting to experiment much, however I still wanted to share it as I think its a solid build.
This is an Endgame build for people past the campaign, for leveling I would suggest utilizing Raging Spirits, Unearth, Skeletal Arsonist and using Detonate Dead on corpses your minions kill. Leveling for Blood Mage can be quite rough, I suggest skipping normal lab for quite awhile. Enfolding Dawn and Oaksworn are AMAZING leveling uniques. (spirit = more minions).
I will say the build can be a bit clunky as you are relying on your minions being alive as well as moving them around through the map to detonate them, occasionally running out. Check out the video linked to see the build.