Meister (soul eater, needs a demon weapon player)

Meisters are individuals with exceptional wavelengths who are paired up with weapons should both the meister and weapon have a compatible wavelength. This is based on the personalities of the potential meister and weapon. Should they be compatible, the individual would be able to utilize their chosen partner with ease. However, if one's wavelength isn't compatible, dangerous effects from the rejection can result in injury and possibly death in extreme cases. Meisters are also typically physically fit, being a prerequisite in institutions training meisters and weapons

Meisters can vary in race and even to animals such as the likes of apes. Only demon weapons, however, haven't exhibit abilities of being a meister beyond wielding family member and their weapon forms through a special bond or wielding Excalibur.

Soul Resonance

Soul Resonance (3rd level):

You gain the ability to synchronize your soul wavelength with that of your Demon Weapon. As an action, you can spend a use of your Action Surge to enter Soul Resonance with your partner. While in Soul Resonance, you and your partner gain the following benefits:

• You can communicate telepathically with each other, even over long distances.
• Your attacks deal an extra 1d6 necrotic damage.
• You both gain advantage on attack rolls and saving throws.
• attacks are considered attacks that can harm the soul 
• All movement by the Meister is doubled, climbing is equal to movement and jump height is tripled
• Soul Resonance lasts for 10 minute, after which you and your partner are fatigued and cannot use this feature again until you finish a long rest.

To maintain resonance both weapon and Meister need to make concentration save whenever they take damage. If both fail then resonance is broken if just 1 fail then the duration of resonance is shorted by 1 minute and if both succeed then resonance continues as normal. If resonance is broken by both the Meister and demon weapon failing the save then the weapon returns to their normal form and both are pushed 5 feet apart with no fatigue.  

Soul Perception

Soul Perception (7th level):

Your training as a Soul Eater Meister has given you the ability to sense souls and gain the following benefits:

• You can detect the presence of living creatures within 60 feet of you even through barriers
• You can discern their location and approximate size.
• You can also tell if a creature has a soul or not.
• you can tell if it is a magical construct or undead.
• you gain advantage on insight checks 
• you are able to discern if they are or there is a witch within 80 feet only if they are of equal or lower level 

Demon Weapon Mastery

Demon Weapon Mastery (10th level):

You have mastered the use of your Demon Weapon, gaining the following benefits:

• You can use your Action Surge to make an additional attack with your weapon or an unarmed strike.
• You can now enter Soul Resonance with your partner twice per long rest.
• Your attacks with your weapon deal an additional 1d6 damage of the same type as the weapon.

Soul Perception Mastery

Soul Perception Mastery (15th level):

Your Soul Perception ability has become even more powerful and gain the following benefits:

• You can now detect the emotions and intentions of living creatures within 60 feet of you.
• passively you are now aware of all beings with a soul within 30 feet of you.
• You can tell if they are hostile, friendly, or indifferent towards you.
• You can sense their emotional state (e.g. angry, frightened, happy).
• You are able to sense the soul of a witch of Kishin within 150 feet regardless of level.
• As a bonus action anything with a soul Targeting you has to make a wisdom save or have their next action be revealed.

Death Cannon

Death Cannon (18th level): 

You and your partner can unleash a devastating attack together.

As an action, you can spend 2 uses of your Action Surge to enter Soul Resonance and charge up a Death Cannon or 1 use if you are already resonating. On your next turn, you can unleash the Death Cannon, which deals 10d6 necrotic damage to a single target within 120 feet. The target must make a Constitution saving throw (DC 8 + your proficiency bonus + your Strength or Dexterity modifier) or be stunned until the end of its next turn.

You may also pick one of the following for the attack as an alternative to Death cannon

 

Death Ray

Death Ray: The Death Cannon now deals 12d8 necrotic damage instead of 12d6 but no stun.

Kishin hunt

Melee only 

the striking sides of the demon weapon have transformed into a form your demon weapon choses

After the charging period You can dash to a target within 60 feet and make a melee attack against a single target within 15 feet of your new location, dealing 12d8 necrotic damage on a hit. The target must make a Constitution saving throw (DC 8 + your proficiency bonus + your Strength or Dexterity modifier) or be stunned until the end of its next turn.

If the target dies you can continue to cleave your attack onto the next enemy within 15 feet.

Soul Menace

The Death Cannon now has a 30-foot radius and deals 12d6 necrotic damage to all creatures within the area of effect. Creatures in the area must make a Dexterity saving throw (DC 8 + your proficiency bonus + your Strength or Dexterity modifier) or take full damage, or half as much on a successful save.