Jujutsu Sorcerer

[This Subclass is meant for a personal campaign I'm writing for my friends who are huge fans of the series just like me, but if you like the look of this feel free to use it too! :^) This subclass is written as a kind of template for my players to insert either their own custom cursed techniques onto or ones they like from the show, so this subclass convers the fundamentals of what a jujutsu sorcerer subclass would have, rather than the specifics of what a technique like ten shadows or something custom would have at each level. This subclass relies upon the use of Cursed Energy, but if you want to use this in a typical DND setting it's very possible to replace Cursed Energy with Ki Points, just ask your DM about specifics]
[To clarify, this is only a subclass because of DNDBeyond's homebrew creation rules, if i could make this a class i would]

Jujutsu Sorcerer Monks are individuals blessed with control over cursed energy, both in the manipulation of the world around them as well as in the circulation of the energy flowing through them. They dedicate their lives, should they follow the code of their society, to protecting the weak against the tyranny of cursed spirits and cursed users.

Jujutsu Sorcerers operate in a world dictated by the strength of negativity and evil and shine as exceptions to this darkness, however this alone does not place them into a strict alignment. Due to their time spent amongst the curses of humanity, more often than not they've adopted pessimistic views on society and humanity as a whole, producing individuals who either look out for themselves, or individuals who disregard this and meet a noble but young end. 

Jujutsu Sorcerers typically originate from various schools, such as the New Shadow Style School or Jujutsu Tech, however some sorcerers never pursue these paths, or are reincarnated from an era before these schools existed.

Black Flash

At 3rd level, your understanding of the flow of cursed energy within your body heightens, allowing you to perform a black flash under fortunate circumstances. The requirement to roll a critical hit is reduced by one when attacking a single target with Cursed Energy [including summoned spirits or ranged attacks] or when using a Cursed Tool.

When landing a Black Flash, the requirements to land a critical hit reduces by one once again [To a minimum of 18]. This can only occur on the subsequent hit, if a black flash isn't landed on the attack following a previous one, then the requirements to land a critical hit/black flash resets to 19.  

Binding Vow

At 6th level, you've learned how to fast-track your progress through the use of a divine vow that binds your soul to your word. You can make this vow with either another creature or yourself. When making a vow with another creature, it must be entirely willing to enter that vow, including if it is charmed or otherwise influenced into making one. The penalty for breaking a binding vow varies between the two forms. If a binding vow is broken with oneself, then the benefit gained from that binding vow is forever lost, meanwhile if a binding vow with another person is broken, then an unforeseeable divine punishment is administered unto that person [GM Discretion] 

Making a binding vow with oneself requires give-and-take, such as giving up a daily ritual, exchanging power, or the shifting of one's technique. For instance, if an individual with the ten shadows technique wished to be able to summon three divine dogs instead of two, they may make a binding vow to have the divine dogs be neutral rather than allied summons.
The specifics of each binding vow is agreed upon between a player and the GM, similar in how the character itself is making a binding vow with some omnipotent entity, and whether the details of this exchange is known to the player is decided upon by the GM. The strength of these binding vows scales with the player's level.

A Jujutsu Sorcerer may use binding vows to sacrifice their body in exchange for strengthening an attack in a last-ditch effort to win a battle. Upon reaching 5th level, Jujutsu Sorcerers can choose to force out a black flash from their attack in exchange for immediately suffering a point of exhaustion on that same turn. A black flash summoned through a binding vow in this way will not grant them the benefits of a naturally occurring black flash.

Simple Domain

At 11th Level, you obtain the ability to expand a simple domain, intended as a countermeasure to the guaranteed hit effects of hostile domains. You can use an action and bonus action to expand a simple domain to a radius equivalent to [your wisdom modifier * 2.5ft] to a minimum of 5ft. While within the simple domain, characters are immune to the guaranteed hit effects of a hostile domain, and gain a bonus to saving throws against cursed techniques equivalent to the Simple Domain sorcerer's proficiency modifier. In order to keep the simple domain expanded, you must use both your entire turn to do so, and must make a concentration saving throw when attacked or disrupted from this ritual.

Domain Expansion

Prerequisites: Awakening 

At 17th level, Jujutsu Sorcerers meet one of the requirements to expand their domain. The expansion of one's domain symbolizes the end of their journey as a Jujutsu Sorcerer, reaching the peaks of jujutsu society alongside the realization and visualization of where their technique thrives the most. For instance, a fire-based technique may have their domain be within a volcano, or a touch-based technique being within the palm of the sorcerer's hand. This domain isn't limited entirely to what's most practical or makes sense for the technique however, a character's personality or desires may take priority when shaping this domain, such as a gambler's domain being entirely luck based unlike their innate technique. 

However, Domain Expansion has additional requirements beyond that of experience or training, it requires the sorcerer to undergo a process of self realization. Whether this be a close call with death or finally understanding the shape of their own soul, Domain Expansion is one of the few techniques that even Special Grade sorcerers can lack without this insight. Therefore, in order for a character to be able to use Domain Expansion, their must gain this insight in a way that satisfies the GM; most likely through the fulfilment of their goals, playing true to that character's bonds and flaws. 

 A Character can expend their entire turn performing a Domain Expansion, in which they perform chants and hand-signs in order to raise their Cursed Energy levels high enough to do so. This expansion uses the character's entire turn, and upon the start of their next turn their domain is expanded. For the duration of their domain expansion, the character must have free hands (hand-signs) and be able to use the verbal components (chants). If either of these aspects are interrupted, the character must roll a Concentration saving throw. 

The actual effects of a Domain are referred to as 'Domain Actions', where a separate initiative count is rolled for each potential effect of the Domain. For instance, a character may roll a 19 for their Domain Action, and once that Domain Action's "turn" comes up in the turn order, the sorcerer may choose to use that effect. These Domain Actions vary drastically between each individual sorcerer and technique, however some ideas for custom Domain Actions can be seen below, with the Domain specifically being a stormy ocean, with pirate ships engaged in battle. 

• Domain Action : The pirate ships begin firing upon one another, firing cannonballs along the hull of the ship in a straight line. If a creature is standing within the line of fire, they must roll a DC 16 Dex saving throw, upon a successful roll they take half damage from the canonball. On a failed saving throw, the creature must take 4d10 bludgeoning damage and be knocked prone.
• Domain Action : The storm grows fiercer, every creature inside the domain besides the Domain's creator must roll a DC 16 STR saving throw or be knocked overboard. The waters below are considered difficult terrain, and creatures submerged in the water must roll a DC 14 STR saving throw or sink beneath the waters. For each turn that a character is in the water, submerged or otherwise, they take 3d6 bludgeoning damage as they're battered by waves or 6d6 bludgeoning damage as they're smashed against the keel of the ship.