Medium Domain

Whether it was from a young age or perhaps a more recent development that you haven't quite come to terms with yet, your deity bestowed upon you the gift of communicating with those who have passed on. While the dead can sometimes seem like a curse, the pursuit of this path has great rewards for those who learn how to coexist with the spirits that become connected with them in this life. 

Whispers from Beyond

At level one, you are able to communicate with spirits and they are able to communicate with you. Using the Wisdom (Perception) skill, you can sense any nearby spirits, and upon a successful DC 15 Intelligence save you can converse with them for a duration of 5 minutes with concentration. Upon a failed save, you dissociate for the next ten minutes, and have disadvantage to all rolls until you recover.
Also at level one, you gain Speak With Dead as a level one spell instead of level three.

Channel Ghosts

At level 2, you become able to channel ghosts! Each ghost comes with one skill proficiency, one weapon OR tool proficiency, and one language proficiency - all of which should be related to the ghost's life experience. As you spend more time connected to the spirits, you also gain +1 to an ability score related to your ghosts. These bonuses are only active while being possessed by the ghost. You can channel three times per long rest - at level 11, you can channel four times per long rest - at level 17 you can channel five times per long rest. Refer to the info below for feature progression.

Level 2 - 1 Ghost
Level 3 - 2 Ghosts
Level 5 - 3 Ghosts, 1st Ghost: Add +1 Ability Score Improvement
Level 9 - 4 Ghosts
Level 15 - 5 Ghosts, 2nd Ghost: Add +1 Ability Score Improvement
Level 17 - 6 Ghosts

Divine Protection

At level 6, you are blessed by your deity with additional spiritual protection. You gain Magic Circle as a cantrip, and Spirit Guardians as a level one spell. Magic Missile does not count against your cantrips known on the cleric features chart.

Old Souls

Also at level 6, you have heard lots of stories from your ghosts. You gain history proficiency - if already proficient, double your proficiency bonus for this skill.

Imbue Spirit

At Level 8, you can temporarily imbue a weapon with one of your ghosts, which allows you to add your WIS modifier to all damage rolls made with the possessed weapon. This lasts for six hours and can be used once per long rest.

Armor of the Possessed

At Level 17, twice per long rest you can channel all six ghosts connected to you at once - your AC becomes 10 + your WIS modifier + your CON modifier, and you gain resistance to physical, radiant, necrotic, and psychic damage for a duration of five of your own turns. You can cast this as a bonus action.