Path Of The Conflicted Soul

These divine casters may be piteous clerics who may have encountered darker powers or cursed warlocks who have gained leverage on their patron with help of the light of a god of redemption. Regardless of their origin these casters embody two conflicting powers that fight for influence over their soul. Being exposed to both the life and the darkness means that these casters are able to wield both to their advantage but unable to completely stray to far to or from on side. 

Bonus Proficiency

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

Disciple of Life

Also starting at 1st level, your healing spells are more effective. Whenever you use a spell of 1st level or higher to restore hit points to a creature, the creature regains additional hit points equal to 2 + the spell’s level.

Channel Darkness: Siphon

Starting at 2nd level, you can use your Channel Darkness to heal yourself.

As an action, you present your cursed brand and evoke dark energy that can restore a number of hit points equal the damage you deal on you allies. Each creature within 10 feet of you that is aligned with you takes 1d4 necrotic damage. This damage can not be avoided if the creature is unaware of it's effects. This spell can not be used on unwilling knowledgeable creatures.

Cursed Healer

Beginning at 6th level, the healing spells you cast on others damage enemies as well. When you cast a spell of 1st level or higher that restores hit points to a creature other than you, enemies within 30 feet of you take damage equal to 2 + the spell's level. 

Contraditictive Strike

At 8th level, you gain the ability to infuse your weapon strikes with both divine and dark 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 radiant and necrotic damage to the target. When you reach 14th level, the extra damage increases to 2d8.

Restorative Wraith

One per long rest the caster can channel both the darkness and the light that resides within them and create a wave of energy that heals all allies and damage all enemies within it's range for 5d6 HP.