the oath of the shadows solely on dealing more damage and necrotic damage at that via the use of divine smite and class features.

Channel Divinity

When you take this oath at 3rd level, you gain the following two Channel Divinity options.

Shadow Weapon. As an action, you can imbue one weapon that you are holding with dark energy, using your Channel Divinity. For 1 minute, you turn the weapon into a spell casting focus for your spells. If the weapon is not already magical, it becomes magical for the duration.

You can end this effect on your turn as part of any other action. If you are no longer holding or carrying this weapon, or if you fall unconscious, this effect ends.

Raise the Shadows. As an action, you present your holy symbol and speak a prayer summoning a minion made of physical shadow, using your Channel Divinity. For 1 minute this creature will be your ally, it has 5 hit points, an ac of 10, a to hit modifier of +1, a melee range of 5ft and can do 1d4 necrotic damage.

Aura of Shadows

Starting at 7th level, you and friendly creatures within 10 feet of you can’t be charmed or frightened while you are conscious.

At 18th level, the range of this aura increases to 30 feet.

Divine smite: corrupted

begining at 15th level your divine smite becomes corrupted and does necrotic damage instead of radiant damage.

Shadows Wrath

At 20th level, as an action, you can summon 3 physical shadows, they all have the same hit points and AC as you, a melee range of 5ft, a to hit modifier of +5 and do 2d8 necrotic damage.