In the shaded groves of the Summer Court, among the proud fey, the art of spirit bonding was born. This ancient technique allows the user to fuse their soul with an elemental spirit, forging a pact that grants them the ability to use said spirit's powers. Whether through an oath or through battle, the contract is sealed, the spirit becomes part of the creature, and the creature becomes something more.

But the path is dangerous, as binding even a minor elemental risks losing oneself in the process, while attempting to claim the essence of greater spirits borders on suicidal. Only the strongest survive the trial and, those who do emerge as Spirit-Bound Vessels, wield the raw elemental power with their every strike, as they become able to channel that same energy through their body.

Level 3: Spiritual Sense

Your connection to the spirit world grants you insight beyond the reach of ordinary senses. By examining an area, structure, or object for 1 minute, you can determine whether it has been in the presence of a spirit. This manifests through subtle sensations, such as a warm breeze, a faint whisper, or a pulse in the ground; depending on the nature of the spirit involved.

In addition, as an action, you can attune yourself to the emotional resonance of your surroundings within a 60ft radius. This does not reveal precise information, but instead provides a general sense of the area's emotional state—such as peaceful, tense, disturbed, or watchful—as well as the presence of unnatural disturbances like blight, corruption, or unnatural pollution.

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

* What is considered as a spirit is up to the DM. Either way, any elemental or any creature that belongs to the ethereal plane should be considered as one.

Level 3: Spirit Fusion

You have forged a pact with a powerful spirit of nature. Choose one of the following spirits to bond with: Wildfire, Blizzard, Storm, Tremor or Corrosion. This spirit becomes your 'Primary Spirit', and it is bound to you until the moment of your death.

You’ve learned to draw on the raw power of your bound spirit, though doing so places a strain on your mortal body. As a bonus action, you take damage equal to 10% of your maximum hit points (rounded down). This damage is of your Primary Spirit’s type and can't be reduced or avoided in any way. Then, immediately after taking this damage, your body becomes a vessel for the raw spiritual energy. For the next 10 minutes, you gain the following benefits:

• Your weapon attacks and unarmed strikes deal 1d4 extra damage of the type related to your Primary Spirit (as shown at the table right below). This damage increases to 1d6 for your unarmed strikes when you reach level 11 in this class, as the power of the spirits is easier to draw out when you channel it through your body.
• When you hit a creature with a weapon attack or an unarmed strike, you can apply your Primary Spirit’s 'Special Condition' to that target. You can do this only once per turn.
• You gain resistance to the damage type associated to your 'Pimary Spirit'.

Elemental Spirit	Damage Type	Special Condition
Wildfire	Fire	The target catches on fire, receiving fire damage equal to your proficiency bonus at the start of each of its turns. The flames can be extinguished if the creature uses an action, or one attack (if it has multiattack) to douse them. This damage increases to double your proficiency bonus whenever you reach level 11 in this class.
Blizzard	Cold	The target's speed is reduced by 5 feet. Increasing at level 7 to 10 feet, level 11 to 15ft, level 15 to 20 ft and level 18 to 25 ft.
Storm	Lightning	Each creature of your choice within 5ft of the target receives 1d4 + your proficiency bonus in lightning damage. When you reach level 11 this damage increases to 1d6 and the range becomes 10 feet
Tremor	Thunder	The target has disadvantage on dexterity saving throws until the start of your next turn. When you reach level 11 in this class, it also has disadvantage on strength saving throws.
Corrosion	Acid	The target's next attack roll receives a penalty equal to half your proficiency bonus (rounded down). Whenever you reach level 11 in this class, this penalty is applied to all attacks rolls it makes until the start of your next turn.

 

You can use this feature a number of times equal to your Constitution modifier (minimum one), and you regain all expended uses when you finish a long rest.

Level 7: Spiritual Imprint

You have become so used to your bound spirit that it has left powerful imprint in your very being. You receive both the major and minor imprint of your Primary Spirit, as shown in the table below: 

Bound Spirit	Major Imprint	Minor Imprint
Wildfire	You exude a constant aura of heat, maintaining a temperature of 32ºC/90ºF within 30 feet of you. In addition, you are immune to the effects of extreme heat.	You learn the 'Control Flames' cantrip. Additionally, you can ignite any flammable object or substance you touch, as long as it isn't being worn or carried.
Blizzard	You exude a constant aura of cold, maintaining a temperature of 20ºC/68ºF within 30 feet of you. In addition, you are immune to the effects of extreme cold.	You learn the 'Shape Water' cantrip, and you can manipulate snow with it as if it were water.
Storm	You can detect active electrical currents within 30 feet of you, allowing you to automatically sense any powered device, mechanism, or construct in that range.	By subtly influencing electrical impulses in brains, you learn the  'Message' cantrip.
Tremor	You are finely attuned to vibrations through your own movement. As you travel, you can map terrain within 30ft of you with perfect accuracy. You can't become lost by non-magical means and can detect natural shifts in the earth, such as cave-ins, collapses, or underground rivers.	You learn the 'Mold Earth' cantrip.
Corrosion	You can corrode most surfaces by touch (excluding gold or platinum). If the material is organic, you create a 5ft indentation of your height for every 1 minute you touch it. If inorganic, the same indentation takes 10 minutes per 5ft.	You can choose to age an object you touch, causing it to degrade as though 1 year has passed per every minute of contact. This feature can only affect a single object at a time and does not work on anything made of gold, platinum, or any sort of magical material.

Level 10: Infused Strikes

When you make an unarmed strike, you can choose either the Vex or Sap weapon mastery property. That attack gains the chosen property.

Additionally, when you make a weapon attack or an unarmed strike, you can choose to replace its damage type with the one associated to your Primary Spirit. This only applies to the base damage of said attack, and doesn't extend to any feature, item or spell that adds damage to it.

Level 15: Spirit Burn

Whenever you would drop to 0 hit points,  you can choose to instead drop to 1 hit point and burn the essence of your Primary Spirit in order to stay in the fight. Your body then erupts with elemental power, forcing all creatures within 30ft of you (excluding yourself) to make a dexterity saving throw (DC = 8 + your Proficiency Bonus + your Strength or Dexterity modifier [your choice]). On a fail, they take an amount of damage equal to your twice fighter level and, on a success, they take half. This damage is of the type associated to your Primary Spirit.

On top of that, you then receive an amount of temporary hit points equal to the amount of creatures damaged * your Constitution modifier, to a maximum of a quarter of your maximum hit points.

You can use this feature once per long rest and, right after using it, you are left physically and spiritually drained. Until you finish a short or a long rest, you suffer a penalty to all ability checks and saving throws equal to half your proficiency bonus (rounded down) .

 

Level 18: Dual Fusion

You have grown strong enough to bind a second spirit to your soul. Choose an additional spirit to become your 'Secondary Spirit'. When you activate your Spirit Fusion feature, your attacks now deal an additional 1d4 damage of your Secondary Spirit’s damage type, alongside the damage from your Primary Spirit.

Your Spiritual Imprint feature now grants you the minor imprints of both your Primary and Secondary Spirits.

As a bonus action, you can shift which spirit holds dominance. When you do so, your Primary and Secondary Spirits swap roles. This process however, is quite taxing on the body; you take damage equal to your fighter level of the new Primary Spirit’s damage type. This damage can't be reduced or avoided in any way. 

You can use this feature a number of times equal to your Constitution modifier (minimum one), and you regain all expended uses when you finish a long rest.