Hat of the mysterious stranger

While wearing this hat you may give the help action as a bonus action.
Rolls helped by you may have 1 die rerolled. The rerolled die must be used in that place. ( example: rolling a 10 and a 8 with a d20 adv roll you can choose the 8 and reroll higher or lower the new roll is used in the place of the 8. )

History

From Enderdragon Encounter

Rarity

very rare Wonderous item