RE: Zero -Starting Life in Another World-, Vol. 23 (Light Novel): Volume 23 - Tappei Nagatsuki

The trials in the Pleiades Watchtower are underway! The promise of untold knowledge and maybe a way to save their friends is what brought Subaru's party here and though they have had some initial success, they're currently stuck, unsure how they can get past Reid Astrea, the legend himself. And if that wasn't enough trouble, Subaru might have finally lost...his memories?!