Assassin's Teapot

This seemingly innocuous teapot has two chambers inside of it.

As an action, you can cause one liquid held within the pot to transmute itself into a type of ingested poison, the actual poison itself depending on the rarity of the teapot. 

Uncommon. The type of poison the liquid is transmuted to is Assassin's Blood.

Rare. The type of poison the liquid is transmuted to is a Pale Tincture.

Very Rare. The type of poison the liquid is transmuted to is either Truth Serum or Torpor, chosen at your DM's discretion. 

Legendary. The type of poison the liquid is transmuted to is Midnight Tears. 

You have advantage on any Charisma (Deception) check using this teapot to try and poison a target.