Unyielding Speed:

• The Withering Blades are unnaturally light and easy to wield, despite the physical curse. When you wield both blades, you gain the benefit of the Two-Weapon Fighting feature. Additionally, when you take the Dash action, your speed is increased by 10 feet for the duration of that turn, and you may make one melee attack with a weapon you are wielding as part of the Dash.

Withering Strikes: 

• On a critical hit with the Withering Blades, the target’s Strength score is reduced by 1 for 1 hour. The target’s Strength cannot be reduced below 5 in this way. This reflects the draining nature of the blades, weakening the victim with each successful strike.
• If the target is already cursed by the Withering Blades, they have disadvantage on their saving throws against the Vital Siphon.

 Vital Siphon: 

• Has one charge and resets on short rest
• Deals 1d6 necrotic damage and the target must make a con saving throw. On a successful save the target takes half damage. You heal half the damage dealt.

The Withering Blades are cursed short swords forged in the depths of an ancient, crumbling ruin. Each blade is engraved with runes that seem to drain the life from the wielder and the target they are fighting with every strike. The swords are unnaturally light and seem to hum with an eerie energy, reflecting their curse — one that steals away your strength while amplifying the lethality of each precise blow.

The Withering Blades were forged long ago by a group of assassins who desired to transcend the limitations of mortal flesh. They sought a way to shun physical strength in favor of speed and precision, creating these blades in the process. However, the power of the blades came at a terrible cost. In exchange for the deadly agility they gained with the swords, they were cursed with permanent weakness. The curse sapped their muscles, leaving them frail and incapable of feats that required raw strength. Only those who were willing to embrace this vulnerability could wield the blades—and thus, they became weapons for the swift and the elusive, not the strong.

Proficiency with a Shortsword allows you to add your proficiency bonus to the attack roll for any attack you make with it.

Notes: Bonus: Ability Score Maximum, Vital Siphon: Once per short rest, after making a successful melee attack with either of the Withering Blades, you can siphon life energy from the target. The target must make a Constitution saving throw (DC = 8 + your proficiency bonus + your Dexterity modifier). On a failed save, the target takes 1d6 necrotic damage, and on a success the target takes half. You heal for half the necrotic damage dealt., Finesse, Light, Vex