Unholy Death Knight

Recommended Raiding Build

• Tier 1 - All will serve or clawing shadows
• Tier 2 - Unholy blight
• Tier 3 - Utility row, the choice depends on what you need.
• Tier 4 - Soul reaper
• Tier 5 - spell eater or wraith walk depending on what you need (Defensives or Movement Speed).
• Tier 6 - Unholy pact
• Tier 7 - Army of the damned

Recommended Mythic+ Build

• Tier 1 - All will serve 
• Tier 2 - Unholy blight or bursting sores for big pulls.
• Tier 3 - Utility row, the choice depends on what you need.
• Tier 4 - Soul reaper
• Tier 5 - spell eater or wraith walk depending on what you need (Defensives or Movement Speed).
• Tier 6 - Unholy pact
• Tier 7 - Army of the damned

Infected ClawsPassive

All Will ServePassive

Clawing ShadowsInstant

All will serve is just straight up the highest damage talent in a patchwork fight. All will serve makes your raise dead summon an extra skeletal minion that fires arrows that also cleave from your main target so this will be your go-to talent choice. 

Although, in some scenarios where you won't always have a 100% uptime on the boss, then clawing shadows can be picked instead. 

Clawing shadows replaces scourge strike, converting it to 100% shadow damage and gives it a 30 yard range.

Bursting SoresPassive

Ebon FeverPassive

Unholy BlightInstant

Unholy blight is a 45 second cooldown that applies virulent plague and an extra unholy disease that deals damage and stacks up to four times. These stacks increase the damage of your minions by 12% at max stacks, so when combined with the strong cooldowns unholy have (army of the dead, Apocalypse, etc.) it just becomes the strongest talent that unholy has in this row for single target.

In Mythic+, if you're dealing with large pulls, you want to swap out unholy blight for bursting sores.

Grip of the DeadPassive

Death's ReachPassive

AsphyxiateInstant

The third talent row is a player choice/optional row. It provides you with different control and slows, so neither of them is going to have an impact on your DPS, it's all about what you need on the encounter.

Pestilent PustulesPassive

Harbinger of DoomPassive

Soul ReaperInstant

Soul reaper is an execute that deals initial shadow damage and then after 5 seconds, if the target is below 35% health, it activates and deals a large amount of shadow damage. When it comes to raiding, an execute has always been a very powerful choice for the classes that have the option available.

Spell EaterPassive

Wraith WalkChanneled

Death PactInstant

The fourth row is another optional/fight dependent row where you would either go with spell eater if the fight has a lot of magic damage or if there is some sort of magic damage you need to soak. If that's not the case, you have the option to go with wraith walk for more mobility.

PestilencePassive

Unholy PactPassive

DefileInstant

Unholy pact is currently the strongest single target and AoE option. Unholy pact creates a chain between you and your pet when you cast dark transformation that deals shadow damage to all enemies caught in the chain and increases your strength by 5%.

Army of the DamnedPassive

Summon GargoyleInstant

Unholy AssaultInstant

Your best choice here will be Army of the Damned. It’s currently the strongest option for single target and AoE. Army of the damned reduces the cooldown of apocalypse by 1 second and army of the dead by 5 seconds when you cast death coil.