Approach of Haunted Vessel

While many do not enjoy losing control over their own body, some soul-seers see it as a price they must pay to help the dead move on. By allowing their communed spirit a brief control over flesh and bone, the dead can manifest more of their power rather than through by being merely a passenger in someone's body.

Restful Guardian

Upon taking this approach at 3rd level, your spirits guard you while you aren't awake. You gain the following benefits:

Creature's don't have advantage attacking you due to you being unconscious, nor are these attack critical hits due to this condition.
While unconscious, you roll Strength and Dexterity saving throws as if you were conscious.
You can't be surprised while you are unconscious.
If Initiative is rolled and you are involved yet unconscious, you immediately wake up and stand up unless you are unconscious by magical means or by being at 0 hit points.

Relinquish Control

Also at 3rd level, you can forgo bodily control to allow your dead kin to fight for you. As a bonus action, you can let your communion spirit take over. For the next minute, you gain the following benefits:

You gain an additional amount of Communion Talents of your choice from your Communion Spirit's list equal to half your proficiency bonus (rounded down).
You gain an amount of temporary hit points equal to double your level in this class.
When you would fail a Wisdom or Charisma saving throw, you can spend a reaction to reroll the save, taking the new result.

While you are in this state, you can't cast spells of 1st level or higher unless you learned them through Communion Talents. This feature ends early if you drop to 0 hit points or die outright.

You can use this feature a number of times equal to your proficiency bonus, regaining all expended uses after finishing a long rest. You can still use this feature while you have no remaining uses, but doing so gives you a level of exhaustion once the feature ends.

Communion of Minds

At 6th level, you collection of souls guards your mind against trickery. When you would fail a saving throw against being frightened or charmed, you can spend a reaction to spend a use of your Relinquish Control feature. Doing so causes you succeed against the save instead.

Upon using your Relinquish Control feature, you can also release one of your tethered. Doing so gives you advantage against being Charmed or Frightened for the next minute.

Not all Gone

At 10th level, you still maintain a degree of control when giving your Communion Spirits the reins over your body.

Damage can't break your concentration on a spell while you are under the effects of Relinquish Control.
You have advantage on all saving throws when using your Relinquish Control feature.
You lose all levels of exhaustion you gained through using your Relinquish Control feature upon finishing a long rest.

Awakened Wrath

At 14th level, you can fully release control over your body to your Communion Spirit, allowing it to fight for you while you are on deaths door. Upon dropping to 0 hit points or falling unconscious, you can immediately spend a use of your Relinquish Control feature. Doing so now grants you a number of temporary hit points equal to four times your level in this class.

While you have these temporary hit points, you gain the following benefits;

Your Communion Spirit controls your body as if you were conscious and above 0 hit points.
While your body has 0 hit points, you don't roll death saving throws at the start of your turns, nor do you suffer a failed saving throw when taking damage.
Each time your Communion Spirit deals damage to a creature, it deals an additional 1d10 force damage.

Once these temporary hit points drop to 0 or the minute has passed, this feature immediately ends, causing you to fall unconscious if you are still at 0 hit points and gain 1 failed death save.

Once you have used this feature, you can't use it again until you finish a long rest.