This builds are designed solely for the purpose of abusing the cooldowns of Mephisto.

The first build, Unyielding Skulls, can just about eliminate cooldown all together when in a 5 on 5 or even a 1 on 5 fight. Any time you can hit multiple enemies you will be able to follow up almost instantly. You goal is to keep a distance, using Nova defensively for you and your teammates or to finish off opponents, but not as a main damage tool. Your Shade lets you prep an escape by closing the distance to fire a skull or more, and then bounce back. It's other function combines with Shade Lord and Frost Storm to let you use the Shade even defensively since it will let you double your slows and switch with your more predictable shade for a better escape or to keep pressure on a target. You can also rapid fire shade/lord to create a slow zone in a team fight. But that could cost you a few seconds later. Trickery is also a good alternative since it can take advantage of the multiple ports to combine with increased mobility to create a very mobile platform to fire your skulls. Ghastly Armour also resets it's armour timer when you use Shade Lord. Fire off Consume Souls once your skull poking has reduced someone of a good amount of health. Follow up with a port/nova combo if the heroic doesn't do the job fully.

Hysterical Souls is based around firing off Consume Souls as quickly as possible, while still maintaining some damage buffs from Malicious Intent. The idea for not using Abhorred Skull is that the reveal and the more frequent damage is more valuable than the longer cooldown for additional damage. Since you do have teammates, sometimes spread across the map alone, reveal becomes very valuable. The more frequent but lesser damage takes into account the ability for players to fight until very wounded and then retreat. Because of this, a more frequent damage is more dangerous to them since it reduces the amount of time they can be at low health. But if your team lacks the ability to reduce their health, then that's when Abhorred Skull comes in for 'starter' damage so that your team can do the finishing. Animosity helps further cooldown reduction as does Spite. Keep in mind that using Consume to start damage will likely do little to no bonus damage from lost health. So a safer bet would be 'mid-fight' instead of 'early-fight' if you don't want to wait for 'end-fight' casting.

Endless Hatred uses basic attack cooldowns and Lightning Nova mostly. It gets nova shields and speed boosts to better deal basic attacks that have splash affect to get multiple triggers, including passive nova damage. The extended nova timer should create bigger shields which is easier to land thanks to the increased speed, which is also extended from Shade Lord. Durance of Hate rounds things off with some added roots which are easier to land with the increased move speed and allow for more accurate nova damage.

Static Nova combines spell power and nova shield and damage buffs with mobility and a heroic root/silence to land more powered up novas to deal better burst damage.