After you roll for initiative you may choose to roll The Fiend's Dice. If you do so, roll 6 D20's. The next 6 times you would roll a D20 you must choose one of these 6 instead. You can choose which dice to use, you can only choose each dice once, and after using all 6 dice you return to rolling as normal.

While attuned to the Fiend's Dice you have advantage on any roll made with a Gaming Set.