Spirit Vessel

Some sorcerers form a bond between themselves, and an otherworldly being - while most of the time this is the result of an accident, or the fulfillment of an ancient prophecy, the power it brings is the result of two beings in forced cooperation: a weak mortal vessel, and a powerful bound spirit. Whether their troubles be from a mutual distaste for one another, or the vessel struggling to properly channel the power of the bound, both creatures must grow together if they wish to grow stronger.

The One Bound Within

At 1st level, the power of the spirit within starts its awakening.

Choose the creature type of the spirit bound inside you - based on your choice, you gain an additional cantrip and spell, both of which do not count against the number of Sorcerer cantrips and spells you know.

Celestial

You learn the Sacred Flame cantrip, and the Guiding Bolt spell.

Demon

You learn the Eldritch Blast cantrip, and the Hideous Laughter spell.

Devil

You learn the Produce Flame cantrip, and the Hellish Rebuke spell.

Dragon

You learn the Thaumaturgy cantrip, and the Absorb Elements spell.

Fey

You learn the Druidcraft cantrip, and the Faerie Fire spell.

Undead

You learn the Chill Touch cantrip, and the Inflict Wounds spell.

Spiritual Senses

At 1st level, the spirit within you grants subtle enhancement to your natural abilities.

You can add your Charisma modifier to any Wisdom (Insight or Perception) or Intelligence (Investigation) check you make.

Moreover, during the course of a short rest, you can choose to speak to the spirit bound within you, as if you were using the Augury spell. The spirit can provide additional information at the DM's discretion.

Shielding Visage

At 6th level, you can allow yourself to be consumed by the emotions of the spirit within.

As an action, you can expend a number of Sorcery Points, up to your proficiency bonus - when you do, a protective aura in the form of your bound spirit surrounds you for 1 minute. While this aura is active, you gain a number of temporary hit points equal to your proficiency bonus times the number of Sorcery Points expended. At the end of each of your turns, you regain a number of these temporary hit points equal to your proficiency bonus, up to a maximum of the original amount. Your aura ends early if these temporary hit points are reduced to 0.

While this aura is active, you are considered the same creature type as your bound spirit, and register as such to spells and effects that detect a creature's type.

Might Combined

At 14th level, be it through your souls being in sync or merely a cease in bickering, you and the spirit within now begin to amplify each other's power.

When you cast a spell that deals damage while your Shielding Visage aura is active, you can add your Charisma modifier to one of the spell's damage rolls. If the spell forces one or more creatures to make a saving throw when you cast it, you choose one target to make its saving throw with disadvantage.

Perfected Union

At 18th level, the bond between bound and vessel is perfect, as if you were only one being.

When you activate your Shielding Visage aura, you can grant the same number of temporary hit points you gain from your aura to a number of friendly creatures within 20 ft. that you can see equal to your Charisma modifier. These friendly creatures cannot regain temporary hit points.