Video (gameplay + Harton boss fight)
Grant Void Cleave the “fire” tag to maximize the properties of Eternal Eclipse to deliver large AoE hits. This allows you to remain maximally mobile in fights, and provides a different playstyle than the “stand in 1 place and spam melee attacks as fast as you can.”
By adding the “Riftflame” node on the Void Cleave skill tree, you add the “fire” tag in addition to its “void” tag, making it both at once. Eternal Eclipse grants flat void and fire damage every 2 seconds. Using cooldown reduction, we get Void Cleave down as close to that as possible. We also spec Erasing Strike to automatically crit after a Void Cleave to fill the gap of time in between. This lets us alternate between Void Cleave and a Crit Erasing Strike when needed in tight situations, although most of the time, kiting and Void Cleave are all you need to do.
Anomaly grants us crit and cooldown reduction. Lunge to get in on dangerous ranged monsters, and restores a bit of health.
Crit Void Cleaves restore mana, and Rive is chosen as yet another gap filler if needed and restores mana as well.