This is an upgraded version of Celestial Fury that became my kensai player’s kami weapon (tsukumogami) – level 15 class reward. Like all tsukumogami it grows in power as the PC does so the +6 option is also included here:
Susanoo’s Fury
Omen: When you swing Susanoo’s Fury, the sword discharges harmless electrical sparks.
You have a +3 bonus to attack and damage rolls made with Susanoo’s fury. Additionally, it gains one charge whenever an attack made with it deals more than 20 damage in a single blow. It can hold up to 3 charges, but all unused charges disappear when you take a long rest. When you roll a natural 20 on your attack roll, you deal 10 additional lightning or thunder damage. The weapon uses Honor as its key ability whenever it is required.
Point the Way. When Susanoo’s fury is thrown into the air, it always lands on the ground with its top end pointing toward true magnetic north.
Healing Spark. You may expend a charge as a reaction to cast cure wounds on yourself.
Thunder. While attuned to Susanoo’s fury, whenever you score a critical hit the target of your attack becomes stunned until the end of its next turn. Legendary creatures not immune to stun may expend uses of legendary resistance to negate this effect.
Lightning. As an action you can expend one of the weapon’s charges in order to cast lightning bolt as a 3rd level spell. You may forgo using an action and spend two charges to discharge the lightning bolt as part of your attack action. You may make this decision after knowing if you hit or miss. Finally, you may expend an extra charge to increase the spell level by 1 per charge consumed. You are now also resistant to lightning damage.
See No Evil, Hear No Evil. As a bonus action, you can expend one of the weapon’s charges, in order to cast blindness/deafness as a 4th level spell.
Kami Sori (Razor). When you attack a creature that has at least one head with this weapon and roll a 20 on the attack roll, you cut off one of the creature’s heads. The creature dies if it cannot survive without the lost head. A creature is immune to this effect if it is immune to slashing damage, doesn’t have or need a head, has legendary actions, or the DM decides that the creature is too big for its head to be cut off with this weapon. Such a creature instead takes an extra 6d8 slashing damage from the hit.
Trick Weapon. Susanoo can switch form between a katana and dai-katana as a bonus action.
Awakened Kami. Susanoo’s fury is now fully sentient and either takes the name you give it or takes the name Hitotsuki. It has your alignment. Roll on the Sentient Magic Items table to determine its ability scores, communication ability and senses.
+6 Proficiency bonus
- Lady Tomoe’s Lightning. Any lightning damage you ignore due to your lightning resistance is stored within Susanoo’s fury. The sword can hold up to 100 points of lightning damage in this manner. At any time within the next minute, as a free action, you can choose to apply up to 10 points of absorbed electricity damage as additional electricity damage dealt by Susanoo’s fury. You must announce your intent to use the additional lightning damage before the attack roll is made — a miss wastes the charge. This ability can be used only once per round, and the lightning damage used is subtracted from the total held by Susanoo’s fury.
- Call the Storm. Once per week on command, you can use control weather as the spell to call a thunderstorm. You can use this ability regardless of climate or season, though the ambient temperature might affect the type of precipitation the storm delivers.
- Lightning Catcher. When you are hit by lightning damage that allows a saving throw if you succeed you take no damage. On a natural 20 on your saving throw, you can redirect the lightning attack back against the attacker as a reaction.
Tsukumogami
Tsukumogami were man-made items of exceptional quality that had had their kami awakened, either through the skill used in creating them or through their association with great deeds. These items can usually only be attuned or used by a single person. They grow in power as the hero who owns it also grows in fame, honour and power.