Circle of Possession

A lost dark art among druids. Very few know this circle. The few who know it, hide the secret well. They are often shunned by society, who claim them to be witches and monsters for what they can do.

Possession

Pick a willing creature of CR equal to or lower than your one third of your druid level or of a level equal to or less than your level, within 30 feet of you. As a bonus action, you can expend a use of your Wild Shape feature to possess its body and become a new entity for a number of hours equal to half your druid level or until you are incapacitated or decide to drop the form as a bonus action.When you exit the form, the target creature comes back at the space of the entity and you come back into the closest unoccupied space of the target creature. If there are multiple possible spaces, one is picked randomly. All items you are carrying are either dropped or merged into the new form or worn by the new form if possible.

While possessing the creature, your body disappears and combines with the body of the target creature into one single body. The combined entity looks like the target creature and has the same strength, dexterity, and constitution modifiers for skills and saving throws but has the higher of you and the target creature's modifiers for intelligence, wisdom, and charisma skills and saving throws. It is also both you and the target creature's type. For example, if you are humanoid and the target entity is fey, the combined entity will be both fey and humanoid. Otherwise, the combined entity retains the stats of the target creature.

The combined entity can take a turn on both your initiative counts, but only one of you can take the turn each round. If you are combined before initiative is rolled, you both take your turns one after another. You can decide who goes first and who goes next.

While possessing its body, you gain the following benefits.

• The hit point maximum of the new entity is equal to the sum of the hit point maximums of you and the target creature, and the current hit points are equal to the sum of the current hit points of you and the creature.
• When you exit the form, whatever hit points that remain, is split evenly between the two of you. If you exit from dropping to 0 hit points, both of you separate and drop to 0 separately.
• If either you or the target creature has resistance or immunity to a damage type, the combined entity also receives the feature.
• Whenever the combined entity needs to make an ability check or saving throw with intelligence, wisdom or charisma, it can use the higher of the modifiers between you and the target creature.
• If the combined entity has to make an ability check or saving throw with strength, dexterity, or constitution, it has to use the target creature's modifiers.
• You gain advantage for any ability check or saving throw involving intelligence, wisdom, or charisma. If you gain advantage from other sources, you can roll thrice.
• You cannot cast spells in this form that require somatic or material components, but if you cast a spell requiring concentration before possessing the creature, you can continue to concentrate on it in this form. You have to use the target creature's constitution saving throw modifier for any concentration checks.
• Any time the combined entity receives damage, it is taken as you or the target creature taking the entire damage for the purposes of concentration. For example, if the combined entity takes 24 damage, while both you and the target creature are both concentrating on spells, both of you have to make a DC 12 constitution saving throw to maintain concentration on their spells. If only one is concentrating on a spell, only that creature has to make the constitution saving throw. 
• If the target creature has an effect that prevents them from concentrating, like rage or other concentration spells, it does not affect your concentration.
• Features like dark vision and blind sight are also passed on to the combined entity.
• Movement speed of the combined entity is the higher of the two movement speeds between the target creature and you.
• Any condition that either you or the target creature has at the time of possession is carried over to the combined entity form. If the condition ends while in the combined entity form, it is not carried over when you separate.
• If you gain a condition while in combined form, you can decide who the condition stays on when you separate. The other person loses the effect of the condition.

Bonus cantrip

When you are in normal, wild shape, or possessed form you gain the following benefits.

Whenever you or the combined entity has a turn, you can use your action to cast booming blade or green flame blade. The natural weapons of beasts are considered as valid material components for these cantrips.

Possession spells

You gain the following benefits.

• Heal: As an action, you can expend spell slots to gain 1d8 hit points for each level of the spell.
• Minor Shield: As a reaction to an attack roll or the magic missile spell, you can expend a spell slot of any level to make a spectral shield cover you granting you immunity to the magic missile spell, and granting a +3 bonus to AC till the end of your next turn.

Symbiosis

• Haste: As your action, you can expend a third level spell slot or higher, in possessed, wild shape, or normal form to cast haste on yourself or the combined entity.
• Minor Smite: Whenever you or the combined entity, in wild shape, normal, or possessed form, makes a weapon attack, you can expend a spell slot to deal 1d4 extra damage per level of the spell slot. The attack is also considered magical for the purposes of overcoming resistance and immunity.
• Alter self: Whenever in wild shape, normal or possessed form, you use an action to expend a second level spell slot or higher to cast alter self on yourself or the combined entity.

Enhanced Symbiosis

You gain the following benefits in normal, possessed or wild shaped form .

• Your walking speed increases by 10.
• Whenever you or the combined entity takes the attack action on your turn, you or the combined entity can use your bonus action to make another attack.
• You get a +2 bonus to AC.

Ultimate Possession

When in possessed form, you can cast spells that do not require a material component.

If a spell requires a material component, but can use an arcane focus, if the combined entity is carrying an arcane focus, you can channel your spells through the same focus.

You can use a bonus action to expend a wild shape use to turn into a banshee, ghost, or two wild shape uses to turn into a wraith.

(If you possess someone as a ghost and your wild shape timer runs out, you come back to the closest unoccupied space near the creature)