Widowbite
Weapon (Whipblade), rare
A finely crafted blade of dark metal. There are three runes etched into the spine of the blade. The first two glow dimly.
You gain a +2 bonus to attack and damage rolls made with this magic weapon. While attuned to Widowbite you may use your Object Interaction to toggle between solid blade form and whip form. Longsword form: 1d8 slashing (Versatile 1d10). Whip form: 1d6 slashing (reach).
Widow's Kiss (PB/LR): After hitting an enemy with the sword you can choice to apply 3d10 poison damage. For attacks made with this ability Resistance is ignored and Immunity is considered to be Resistance. After hitting an enemy with Widow's Kiss they must make a DC16 Constitution saving throw. On a failure, the creature is poisoned for one minute.
Spider's Bane (PB/LR): After hitting a creature with the sword you can choose to have it suffer from the effect of the Bane spell.
Rip & Bleed: If the target is hit by a whip form attack they lose 1d10 hit points at the start of each of its turns due to a bleeding wound caused by the whip. Each additional hit on the wounded target with the whip form attack increases the bleeding damage by 1d10. A creature can take an action to stanch the wound, and the wound also closes if the target receives magical healing.
Spider Climb (1/SR): As a bonus action you can cast Spider Climb without expending a spell slot. This spell does not require concentration.