Originally Posted by
theblackharvest
Wreck havoc, shadowburn and sac grimoire are no brainer in this fight imo. Rain of fire is not worth it since its fixed location and dmg over time. The only thing you could experiment is with the second row of talents. You could try mana tap since it enhances the shadowburn cleave at the cost of more lifetaps but dunno if the tradeoff is worth it or cata for burst aoeing the adds.
Also on another note, you dont have to havoc the boss. Remember that you get shards also from the havoced target if he dies. You could abuse this to get double the shards since havoc has no cd and you can reapply it (thought there is a point that you ll gain more shards than you can spend)