Undeath Domain

The gods of undeath are always looking for ways to expand their armies of undead creatures. They are evil by nature, but cannot create anything of their own, instead perverting and corrupting that of other, more moral, gods. Their clerics are invariably evil, and are normally skilled necromancers themselves.

Bonus Proficiency

When you choose this domain at 1st level, you gain proficiency with heavy armor.

Disciple of Death

Also starting at 1st level, your necromancer's spells are more effective. Whenever you use a spell of 1st level or higher to inflict necrotic damage, the creature loses hit points equal to 2 + the spell's level.

Channel Divinity: Control undead

Starting at 2nd level, you can use your Channel Divinity to control undead.

As an action, you present your holy symbol and evoke necrotic energy that can take control of undead creatures. All undead within 30 feet have to make a Wisdom saving throw. Creatures that are immune to features that turn undead automatically succeed on the saving throw, and you can choose a number of creatures equal to your cleric level to automatically succeed as well. If they fail the throw, they have to follow a command that you give (all affected creatures follow the command). Before following the command, they can make a Constitution saving throw. If they succeed, then they don't follow any commands that are directly harmful to them, but follow all other commands to the best of their abilities. If they fail, they will follow all commands to the best of their abilities. Any undead with an Intelligence score greater than 5+[your cleric level] who fails the first save, but succeeds on the second one, will attack you immediately, dealing 1d10 bludgeoning damage × [your cleric level]. The DC for all these saves is equal to 5+[your cleric level]+[your wisdom ability modifier].

Necrotic Resistance

Also at 2nd level, you gain resistance to necrotic damage.

Divine Destroyer

Beginning at 6th level, the spells that inflict necrotic damage that you cast on others heal you as well. When you cast a spell of 1st level or higher that inflicts necrotic damage on a creature, you regain hit points equal to 2 + the spell’s level.

Necromancer's Strike

At 8th level, you gain the ability to infuse your weapon strikes with divine energy. Once on each of your turns when you hit a creature with a weapon attack, you can cause the attack to deal an extra 1d8 necrotic damage to the target. When you reach 14th level, the extra damage increases to 2d8.

Demigod of undeath

At 17th level, you turn into an undead by your deity turning you into a demigod of undeath. This grants you resistance to bludgeoning, piercing and slashing damage from nonmagical weapons, and resistance to psychic damage. However, it makes you vulnerable to fire damage. Also, your body disappears when you reach 0 hit points, granting you immunity to all damage. You regain all hit points (unless you have 0 hit points), and gain the benefits of a long rest, at midnight each night. You are unaffected by any spell or feature that says that it doesn't affect undead, and can be affected by spells and features that only affect undead; however you are immune to features that turn undead.