You exude an aura of bad luck around you that affects both friend and foe alike.
As a reaction, whenever a creature within 60 feet of you makes an attack roll, ability check, or saving throw you may have that creature roll with disadvantage. This can be done after the first roll is made but not before the outcome is determined.
Using this ability exhausts its charge. The charge refreshes after a short or long rest. Additionally, you or an ally within 60 feet of you may choose to make an attack roll, ability check, or saving throw with disadvantage in order to refresh this ability. (You may ask your DM to make other players aware of this feat. Allies getting disadvantage to refresh your charge must be ok with this. No one likes someone bossing them into rolling poorly.)