Unused and Cut Content

Abundance and Decay Twinblade / Abundance Twinblade
The Abundance and Decay Twinblade (豊穣と腐敗の両刃剣) and Abundance Twinblade (エブレフェールの両刃剣) are two cut twinblades. Text strings and a set of icons exist that describe them, as well as two skills presumably intended for them (Death Monarch and Miquella's Hidden Blade, detailed below), though it is unclear which twinblade the icons belong to.

They would have had the EquipParamWeapon IDs  (Abundance and Decay) and   (Abundance).

Heretic's Hook
The Heretic's Hook (異教の鉤鎌) is a cut reaper that would have had the EquipParamWeapon ID.

Sharktooth Curved Sword
The Sharktooth Curved Sword is a cut curved sword that would have had the EquipParamWeapon ID. It is essentially a retexture of the Scavenger's Curved Sword, and both descriptions even mention that the notches look like shark teeth.

"Celebrant's Torch"
The "Celebrant's Torch" is a cut torch that would have had the EquipParamWeapon ID. No content exists for it except for its icons. The name comes from the unique Celebrant north of the Minor Erdtree in the Altus Plateau that carries this weapon, and likely would have originally dropped it. This Celebrant in particular appears underdeveloped, as she has no attacks other than the poison blood spray and the ability to throw Fire Pots, and frequently stops attacking altogether.

Unnamed straight swords
Icons for three unnamed straight swords can be found, but there are no names, descriptions, or IDs associated with them.

Spinning Reaper
Spinning Reaper (回転薙ぎ) is a cut skill with the  ID. It likely would have been an Ash of War, but no string for it is in.

Wicked Stance
Wicked Stance (邪の構え) is a cut skill with the  ID. No description of the skill can be found in English or Japanese, and the only remainder of its existence is in, where it is listed as an Ash of War.

Invisible Arrow
Invisible Arrow (不可視の矢) is a cut skill with the  ID. No Japanese description of the skill remains. It would have been an Ash of War.

Death Monarch
Death Monarch (死蝶の舞) is a cut skill with the  ID. It was likely intended for the cut Abundance and Decay Twinblade.

Miquella's Hidden Blade
Miquella's Hidden Blade (ミケラの秘剣) is a cut skill with the  ID. It was likely intended for the cut Abundance Twinblade.