How To Improve As Unholy Death Knight — Shadowlands 9.0.2

Because you can have 3 Runes recharging at the same time, any time you are holding 4 or more Runes, you are effectively capped on runes and wasting potential Rune regeneration. There is never a point in your play where it would be valuable to not cast anything, or where you need more than 3 Runes saved up; always keep 3 Runes on cooldown.

Similarly, every point of Runic Power you generate when already at maximum Runic Power is a fraction of a lost Death Coil. If you are using the Unholy Frenzy build, then make sure you are low on Runic Power before casting Unholy Frenzy so you can maximize Scourge Strike casts during the uptime of this cooldown. There are no situations where it would be better to spend a Rune than it would be to avoid capping Runic Power.

In fights with AoE, you will be saving Death and Decay when multiple targets come up. Due to Death and Decay causing your Scourge Strike to cleave, you benefit significantly from already having Festering Wound stacks already on the target. This becomes even more important if you are using the talent Bursting Sores. If you are running Bursting Sores, then you also benefit from applying at least 1 Festering Wound to all targets you will be cleaving before casting Death and Decay. Since Death and Decay causes your Scourge Strike to cleave all targets, this also causes your Scourge Strike to pop any Festering Wounds on the targets it is cleaving.

The new version of Soul Reaper generates 2 Runes when it is cast. In order to keep 3 Runes regenerating, you want to make sure that you are casting Soul Reaper at a maximum on 1 Rune available.

Your pet Ghoul has 3 attacks called Claw, Gnaw, and Leap. You want to make sure all of these are set to auto cast by right clicking the ability on your pet action bar. These abilities do add a significant amount of damage so having them turned off will lower your damage. The only ability that you may want to turn off in certain fights is Leap because when your Ghoul is under the effects of Dark Transformation, casting Leap will interrupt and stun the target for 2 seconds.

Virulent Plague is your main DoT and provides a significant amount of damage. This DoT like many others does have the effect of Pandemic. However Outbreak constantly refreshes itself for 6 seconds, making Pandemic add about... 3 seconds to Virulent Plague. This makes it important to spend as little Runes as possible refreshing Virulent Plague by refreshing it as close to the expiration as possible (about <1 second left).

The defensive cooldown Anti-Magic Shell only absorbs magical damage therefore making it useless when it comes to physical damage. A common mistake is people casting it to protect against physical damage and not gaining the benefit of a defensive absorb or the Runic Power generation. Make sure you know if an ability from a boss is a physical or magical ability.