Knife of the Undermountain King

The Knife of the Undermountain King is a very rare +2 shortsword which increases the frequency of scoring Critical Hits and grants  Advantage against obscured enemies.

Snatched from the realm of the mad wizard  Halaster Blackcloak, this knife became a prized keepsake of a duergar king.

Properties

Damage: 1d6 + 2 (3~8) + Strength or Dexterity modifier ⁠Piercing
Details:  Shortswords;  Rarity: Very rare; Enchantment: + 2;  One-Handed;  Finesse;  Light;  Dippable;  Melee: 1.5 m (5 ft);  Weight: 0.9 kg (1.8 lb);  Price: 480 gp / 1200 gpH^Honour; UID
MAG_Duergar_Sword_KingsKnife

UUID
025e162a-45ec-4f4c-89da-04d8e8dfe606

Stats
MAG_Duergar_Sword_KingsKnife

The holder of this item gains:

Organ Rearranger: Reduce the number you need to roll a Critical Hit while attacking by 1. This effect can stack. When you roll 2 damage or less, reroll the dice, taking the highest result.

Shadow Blade: You have  Advantage on  Attack Rolls against Lightly or Heavily Obscured targets when using this blade.

If you have proficiency, equip in main hand to gain:

 Flourish (): Feint an attack to possibly throw your opponent  Off Balance. ( Recharge: Short rest.)

 Piercing Strike (): Stab an enemy and possibly inflict  Gaping Wounds. ( Recharge: Short rest.)

Notes included from Organ Rearranger:

Organ Rearranger stacks with other passive effects that increase critical hit range, including for ranged attacks and spell attacks.
Organ Rearranger's damage reroll only applies to melee weapon attacks. It does not apply to any other attack type, including  Throw attacks using the Knife of the Undermountain King itself. When dual-wielding melee weapons, both weapons benefit.
All damage dice of an attack can be rerolled, not just the weapon's base damage die.
Organ Rearranger's damage reroll stacks with itself (via a second  Knife of the Undermountain King, obtained through the  King's Knife or  Invoke Duplicity bugs) or with  Twist of Fortune when dual-wielding. The average improvement of the second reroll is smaller than the first one.

While active, Shadow Blade provides  Advantage to both mainhand and off-hand equipped melee weapons.
Prior to Patch 8 Hotfix 1, Shadow Blade granted advantage to all attack rolls when active. This was changed to only melee weapon attacks.