Boon Chisuke - of Cursed Blood Weapon

You touch a melee weapon and it becomes cursed (see bottom) until a ritual that takes 8 hours and a remove curse. While the weapon is cursed you can’t curse another weapon this way. You are considered attuned to it although it does not use your Attunement slot. You can use the weapon as a conduits for your blood and curses. It counts as a blood weapon. Damage from your curses and necrotic damage you deal bypasses immunity unless the target is immune to all damage such as invulnerability spell. Targets can’t be immune to your curses and you can apply your curses through all attacks and considered part of the weapon attack.

When the weapon deals damage to a creature with blood the weapon draws blood from them. You curse the creature with a Blood Curse (see below) depending on their creature type that lasts 1 minute or until the end of combat which ever happens first. The curse can not exist outside of combat. A creature can only be cursed with one creature blood curse and only one creature can be cursed of each creature blood curse below at a time.

**Blood Cursed**. When the cursed creature hits with a weapon attack it deals 2d6 extra damage depending on the cursed creature’s type labeled as Blood damage type. Additionally when the cursed creature is hit with an attack it takes additional 2d6 damage depending on the cursed creature’s type creature type labeled as Cursed damage type. 

Aberration - When the cursed creature cast a spell or activate an ability that deals Psychic damage that would affect multiple creatures, it only affects one. Blood damage is Psychic damage. Cursed damage is Force.

Beast - Creatures have advantage to hit the cursed creature with weapon attacks. Blood and Cursed damage is the same as the base damage type of the attack.

Celestial - Creatures that hit the cursed creature with a melee weapon become blessed gaining a bonus 1d4 to hit and a bonus 1d4 to saving throws. Blood damage is Radiant. Cursed damage is Necrotic

Dragon - The cursed creature looses blindsight and all other creatures within 30 ft of it gain invisible condition. Blood damage of the same type as the dragon’s breath or Necrotic damage if it doesn’t have one. Cursed damage is Piercing.

Fey - A magical illusion surrounds the cursed creature causing missed attacks against it to hit 50% of the time. Blood damage is Psychic. Cursed damage is Slashing.

Fiend - Attacks the cursed creature makes are at disadvantage. Blood damage is Necrotic. Cursed damage is Radiant.

Giant - The cursed creature and it’s equipment shrink by one category in size decreasing its maximum hit points by an 50. Blood damage of a type the giant has vulnerability, resistance, or immunity to or Necrotic if none. Cursed damage is Force.

Humanoid - Creatures that hit the cursed creature invoke the mastery of the weapon of any, even if the creature that made the attack does not have a weapon mastery. Blood and Cursed damage is the same as the base damage type of the attack.

Monstrosity - When the cursed creatures hits a creature, the creature hit may take a reaction to make an attack with a weapon within range or reach reducing damage dealt by the cursed creature by the damage the cursed creature took. Blood damage is Acid. Cursed damage is psychic.

Most constructs , Elementals, Oozes, Plants, Undead don’t have blood but if they do:

Construct - Force and Thunder Damage dealt to the cursed creature is doubled. Blood and Cursed damage is Force.

Elemental - Damage dealt to the cursed creature can be transmuted into the same type as the Cursed damage. Blood damage is damage of a type the elemental has a resistance, or immunity to or Necrotic if none. Cursed damage is dependent on the Blood damage. If Acid then Thunder, if cold then Fire, if Fire then Cold, if Lightning or Thunder then Acid, if necrotic then radiant, if any other damage type then force.

Ooze - When the cursed creature is hit with a weapon it must make a dexterity save against the attack-roll total. On fail it takes addition damage equal to the damage taken from the original hit. Blood damage is Acid. Cursed damage is Thunder.

Plant - When the cursed creature is hit with this weapon it must make a dexterity save against the attack-roll total. On fail they are grappled by plant vines with AC equal to the attack-roll and hit points equal to the damage dealt. Blood damage is Poison. Cursed damage is Fire if the cursed creature is vulnerable to fire or Necrotic otherwise.

Undead - When the cursed creature is hit with this weapon it make a constitution save against the attack-roll total. On a fail they lose maximum hit points equal to the damage dealt. Blood damage is Necrotic. Cursed damage is Radiant.

Curse. This weapon is cursed it extends the curse to you. As long as you remain cursed, you are unwilling to part with the weapon, keeping it within reach at all times. You also have Disadvantage on attack rolls with weapons other than this one.