I have one but it’s gonna be shelved to time where I find some defense from somewhere. 
It’s Ludrigan Conjurer with 5 storm totems. It have over 100% crit with big lightning modifier. Definitely 6 minutes potential but not enough sustain. When I have opportunity will link GT.
Another cool concept is chaos Oblivion. But is cool on words and not in practice. Maybe Bramblevine Sentinel?