Reckoning Dice is a sub-boss found on the 211th floor of Tartarus. It impedes the player's progress and must be beaten to proceed.
The Reckoning Dice is only vulnerable to physical attacks, but can cast Tetrakarn to cover this vulnerability temporarily. Bring Aigis for this fight, especially if she has her Pallas Athena Persona - when the Dice casts Tetrakarn and Aigis has her turn next, enable Rush mode to ensure she cancels it without harm, due to her resistance to Pierce.
Reckoning Dice appears on the 7th and 8th Path of Yomotsu Hirasaka within the Midnight Channel. It can also be summoned to battle by the Brilliant King. While not flagged as a Weakness, it will take 50% more damage from Physical attacks and six times as much damage from Almighty attacks. After being defeated, it may drop Vengeance Steel. Selling 10 Vengeance Steel at the TV extension of Daidara will unlock the Kashin Koji daggers for Yosuke Hanamura.