Second Soul

When you gain this origin at 1st level, you have a second soul in your body, called your secondary soul. Your primary soul, represented by your proficiencies and class levels, is typically in control of your body. However, you can concentrate for 1 minute (as if you were concentrating on a spell) to allow your secondary soul to take control of the body, or to allow your primary soul to take control if your secondary soul is in control. You can do this at the end of a short or long rest without spending any additional time to do so.

Your secondary soul has the same ability scores, race, and background as you. Choose a class for your secondary soul; it gains the proficiencies and features of that class as if it had gained one level in it. Whenever your primary soul gains a level in this class, your secondary soul also gains a level in the chosen class. Any of that class' features that would normally use Intelligence or Wisdom instead use Charisma. If the class has the Spellcasting or Pact Magic feature, your secondary soul has a separate list of known spells or prepared spells. Your secondary soul cannot multiclass, and if your primary soul gains levels in a class other than sorcerer, the secondary soul's level does not increase. Your secondary soul cannot gain the Ability Score Improvement feature, and cannot benefit from any feature that would permanently increase its ability scores.

When your primary soul is in control, you can use all of your class features and benefit from all of your proficiencies, but none of the features or proficiencies of your secondary soul. Conversely, while your secondary soul is in control, you can use all of its class features and benefits from all of its proficiencies, but none of the features or proficiencies of your primary soul. Both souls can use any features gained from your race, background, or feats. Whenever you take a short or long rest, any features or resources from both souls' class that would be regained is regained for both souls, regardless which one is currently in control (this also applies to preparing spells at the end of a long rest or features that work similarly). Both souls share uses of any feature that they can both use, such as a racial feature that can only be used once per long rest.

Regardless of which soul is in control, both souls can use and benefit from features gained from this subclass, and both souls share the same hit points. The souls can mentally communicate with each other.

Will of Two Minds

Also at 1st level, your mind is more resilient by the nature of having two consciousnesses. You have advantage on saving throws against being charmed or frightened. Additionally, one soul can stay awake as the other sleeps. When you take a long rest, you enter a motionless, inactive state for the duration of the rest instead of being rendered unconscious. While in this state, you are fully aware of your surroundings and can hear and see as normal.

Relinquish Control

At 6th level, your souls can quickly transfer control when the need is great enough. You can have one of your souls take control of the body as an action, rather than spending 1 minute to do so. When you reach 10th level in this class, you can now have a soul take control as a bonus action instead of an action, or as a reaction to making an initiative roll (unless you are surprised).

You can use this feature a number of times equal to your proficiency bonus, and you regain all expended uses when you finish a short or long rest.

Supernal Awareness

At 14th level, while one soul is in control of the body, the other is watching their back. You have blindsight out to a range of 10 feet, and can effectively see anything that isn't behind total cover, even if you're blinded or in darkness or it is invisible. Additionally, no attack roll can have advantage on you while you're not incapacitated.

Two As One

At 18th level, both of your souls can briefly control your body at once. As a bonus action on your turn, you can activate this feature to allow both souls to take control for 1 minute. For the duration, you can use and benefit from the features and proficiencies of both souls. Once the effect ends, you gain one level of exhaustion and can't use this feature again until you finish a long rest.