That Time I Got Reincarnated as a Slime: Clayman's Revenge

After suffering a humiliating and fatal defeat at the hands of Rimuru Tempest during the Walpurgis banquet, Demon Lord Clayman expects eternal oblivion. Instead, he jolts awake decades in the past with his memories of future ruin completely intact. Granted an unexpected second chance via a mysterious time loop, the cunning marionette master realizes his original arrogance and petty scheming caused his demise. Determined to survive, Clayman resolves to reform his behavior, treat his fellow Moderate Harlequin Alliance comrades with genuine affection, and avoid making an enemy of Rimuru at all costs while maneuvering the dangerous politics of the underworld.