The endless hunger will soon take hold of you, death knight. When it does, you will feel pain immeasurable. There is only one remedy for the suffering: the hunger must be sated.
I give you the key to your salvation.
Chained to the Heart of Acherus are those deemed unworthy of the dark brotherhood. Use the key to free an unworthy initiate. Allow them to equip their gear and battle you for their freedom. Kill and the pain will cease. Fail and suffer for eternity.
Live or die - the choice is yours to make.
Progress
Two lives, one key... Do not fail me, <name>.
Completion
As expected, my chosen knight has triumphed! You are ready, <name>.
Notes
This is the first battle that a death knight will have, and many almost die trying to kill the initiate, as they do not know a proper rotation.
Start with your two diseases, Icy Touch and Plague Strike. You probably have noticed that some of your spells do more damage/ have a special effect against targets with your diseases on them, therefore you should always have diseases on your enemies, unless it is a very weak enemy.
Use Blood Strike twice, using up your blood runes. This is currently your only ability that depends on diseases for high damage.
Now that your blood runes are on cooldown, use Death Coil. This is an example of a spell that uses Runic Power, which you acquire from using abilities that use your runes.
After your runes are back up, you have two choices: re-apply diseases or use Blood Strike. The choice depends on how much hp the initiate still has. If he is close to dead, don't bother applying diseases again. If the initiate still has a good chunk of hp, re-apply diseases and start the rotation over.