Arayashiki

Weapon (odachi), artifact (requires attunement by a creature with a Dexterity score of 18 or higher)

Arayashiki is an unnaturally elegant odachi carried within a completely white sheath so pale that, at a glance, its edges seem to disappear into the surrounding world.

When a creature eligible to attune to Arayashiki first touches its sheath, the weapon reaches silently into that creature's memories. Its otherwise colorless form takes on a subtle hue drawn from what it finds within, as though the sword has chosen to remember something of its wielder for itself.

Arayashiki doesn't merely cut flesh. Its edge can pass through memories, experiences, and the very record of the creatures it wounds.

Arayashiki Save DC

Whenever one of Arayashiki's properties requires a saving throw, the save DC equals:

8 + your Proficiency Bonus + your Dexterity modifier

Arayashiki

Melee Weapon Attack: your Proficiency Bonus + your Dexterity modifier to hit, reach 10 ft., one target.

Hit: 1d10 + your Dexterity modifier Slashing damage.

You use your Dexterity modifier for Arayashiki's attack and damage rolls.

I Will Remember

Arayashiki remembers what others are forced to forget.

Whenever one of Arayashiki's properties successfully severs, removes, or causes a creature to forget one of its memories or abilities, the sword absorbs a fragment of what was lost.

The first time this occurs during a combat, Arayashiki's normal damage increases by 1d10 for the remainder of that combat, causing its normal attacks to deal 2d10 + your Dexterity modifier Slashing damage instead of 1d10 + your Dexterity modifier.

This damage increase doesn't stack with itself.

A normal attack with Arayashiki doesn't cause a creature to forget an ability unless another property of the weapon specifically states that it does.

Seeds of the Storm

You can use Seeds of the Storm twice, and you regain all expended uses when you finish a Long Rest.

As an Action, make one melee weapon attack with Arayashiki against a creature within its reach.

On a hit, the creature takes the attack's full normal damage. The cut is so impossibly precise that the target doesn't immediately perceive the true extent of the wound.

Instead, Arayashiki plants a dormant sphere of slashes within it.

The sphere remains dormant for as long as:

• the current combat continues;

• the affected creature has at least 1 Hit Point; and

• the creature remains within 120 feet of you.

If any of these conditions ceases to be true, the dormant slashes immediately disappear.

Unleash the Storm

While the slashes remain dormant, you can use a Bonus Action on any of your turns to activate them.

The planted wound instantly erupts into a devastating sphere of intersecting cuts centered on the affected creature.

Each creature within 15 feet of the affected creature, including the affected creature itself, must make a Dexterity saving throw against your Arayashiki save DC.

On a failed save, a creature takes 3d10 Slashing damage.

On a successful save, it takes half as much damage.

Once unleashed, the dormant slashes disappear.

Lethe

You can use Lethe once, and you regain the expended use when you finish a Long Rest.

As an Action, make one melee weapon attack with Arayashiki against a creature within its reach.

On a hit, the creature takes the attack's normal damage, and Arayashiki cuts directly into the memories associated with one of its abilities.

The DM determines all of the creature's active abilities that are eligible to be affected and secretly assigns each one a number. Passive traits are excluded by default, although the DM has final authority over which abilities qualify.

The DM then tells you how many eligible abilities the creature possesses, but not which number corresponds to which ability.

Choose one of those numbers.

The ability corresponding to that number is severed from the creature's memory for 1d4 of that creature's turns.

While the ability is forgotten, the creature can't willingly activate or use it.

Because Lethe causes Arayashiki to sever one of the creature's memories, a successful use of Lethe triggers I Will Remember.

For example, if the creature has seven eligible abilities, the DM secretly numbers them from 1 to 7 and tells you that there are seven possibilities. You then choose a number from 1 to 7, and the corresponding ability is forgotten.

A creature can have an ability severed by Lethe only once. Once Lethe has successfully affected that creature, it can never affect that creature again.

If the creature has no eligible abilities, the attack still deals its normal damage, but Lethe has no further effect and doesn't trigger I Will Remember.

Slay the Heavens

You can use Slay the Heavens once, and you regain the expended use when you finish a Long Rest.

You can use this property only if you can clearly identify the creature or being who means more to you than anyone else.

Using Slay the Heavens requires you to sacrifice one of your core memories involving that creature.

The sacrificed memory is removed from you as Arayashiki consumes it to fuel the attack.

As an Action, you draw Arayashiki across reality itself.

For an instant, time appears to stop.

A massive 15-foot rift tears open through the air along the path of your slash, and a violent psychic ripple erupts from it in a 30-foot cone in a direction you choose.

Each creature in the cone must make a Wisdom saving throw against your Arayashiki save DC.

On a failed save, roll 1d4 - 1, to a minimum of 1.

For that many of its turns, the creature is trapped within its own most horrifying memory, forced to experience it repeatedly as though it were happening for the first time.

At the beginning of each of its turns while trapped, the creature can repeat the Wisdom saving throw.

On a successful save, the effect ends immediately.

On a failed save, the creature takes 8d6 Psychic damage and remains trapped for the remainder of the duration.

Once the rolled number of turns has elapsed, the effect ends automatically.

A creature that succeeds on the initial saving throw isn't affected.

左様なら

Once per attunement

Arayashiki can make a creature disappear so completely that even existence itself ceases to remember it.

When an attack you make with Arayashiki reduces a creature to 0 Hit Points, you can use your Reaction to invoke this property.

Arayashiki consumes the creature's entire record, regardless of its size, power, nature, or ferocity.

The creature is erased from existence and becomes one of Arayashiki's own memories.

Its body, remains, history, identity, name, face, distinguishing characteristics, and every other record of its existence are removed from the world.

For all practical purposes, the creature is treated as though it had never existed.

The DM determines how this erasure interacts with extraordinary beings, artifacts, planar entities, or effects capable of operating outside conventional reality.

Once you use this property, your attunement to Arayashiki immediately ends.

Arayashiki will never attune to you again.

From that moment onward, none of Arayashiki's magical properties function for you. In your hands, it is nothing more than a sword.

Each creature can invoke 左様なら only once across its entire existence, regardless of whether Arayashiki later finds another wielder.