Among the rubble, you find a pair of perfectly-preserved chainmail gloves. The gauntlets shine with a light blue glow as you pry the them from between the rocks; and you realize that they make no matter what they rub against, they make absolutely no sound. 

Forged from stolen mithril for the God of Greed himself, these glamorous gloves were said to give their wearer the ability to take whatever they wanted -- but at a cost.

Mithril Fingers:

While wearing these gloves, you gain:

•  +1 to AC
• proficiency with thieves tools (if you did not have it already)
•  +7 to all sleight of hand skill checks

And you cannot have disadvantage on checks to steal an item that does not belong to you or someone in your party. 

Abbathor's Envy:

In addition, you are also constantly aware of the most valuable item on each person you come across. However, if a character you meet has an item worth more than 100gp and you do NOT steal it before your next long rest, you take 2d6 psychic damage upon waking up the next morning (for each item you neglected to steal), and have disadvantage on all rolls to attempt stealing for the rest of the day (ignoring the effect from Mithril Fingers). You cannot suffer from this effect for two days in a row. 

Notes: Bonus: Sleight of Hand, Proficiency: Thieves' Tools, Bonus: Armor Class