"Who the hell is Yanmei?"

A small dagger coated with a sick green ooze.

You have a +4 to all attack and damage rolls while holding this weapon.

This weapon only has one charge.

If the target has less than 15 total health, the knife will simply act like a +4 dagger. But if the target has 15 or more total health and is struck, you can consume one charge and the creature must make a Constitution saving throw with a DC of 19. Then the creature will recieve a 20 ft. penalty to their speed, disadvantage on all attack rolls, lose 2 AC and will take 4d10 necrotic damage at the start of every round for 3 rounds, or half of that if the target succeeds its saving throw.

Meanwhile, the owner of the knife will recieve a 10ft. boost to their speed, and +1 on all attack and damage rolls for 2 rounds.

All charges restore after 4 rounds, but you are still able to use the knife as a normal +4 dagger without consuming a charge.

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

Notes: Poisoned, fighter or a rogue, Finesse, Light, Thrown, Nick