You can do the first 75% of the fight as fast or slow as your heart desires. It is completely consistent throughout that phase. Save your high-DPS cooldowns for the end of the fight - you'll need them. He will occasionally use Death Coil on a random person - you just have to hope the tank doesn't get hit with it. Let the tank have a lot of room on the threat table before DPS begins. Healing isn't particularly problematic, so long as people move out of Void Zones quickly. That is the cause of the majority of his damage. It is easy to avoid the Void Zones because they are preceded by a lovely light desplay of pink runes over the area that will be effective. Just step out and continue doing what you do. If you do not need to be in melee range stand reasonably far away. If you are doing melee DPS avoid the cleave by staying behind him.
When Nethekurse gets to 25% life phase two begins. He stands in place and performs his Dark Spin, which will last until the end of the fight. At this point the tank can move out, as he has very little to offer by way of DPS and standing in melee range will only make the healer's job harder. All the DPS should pop trinkets, cooldowns, whatever they have to kill him quickly. If left in this phase for too long, he will eventually drain the healer and the group will wipe.
Heroic Mode
On heroic mode the fight is virtually unchanged. The major difference is the highly increased damage of the Void Zones. They are easy to avoid, but if ignored will kill a player within two seconds. Everyone shifting a few steps every 5-10 seconds will minimize the damage taken from Void Zones.
