That Time I Got Reincarnated as a Slime Novel Volume 22 is written by Fuse with illustrations by Mitz Vah.

The angel army led by Feldway has collapsed, but the threats are far from over. The motives of Velzard, the oldest female True Dragon, remain an enigma. Meanwhile, Milim is running amok, with Feldway taking full advantage of the chaos-and the most malicious of all creatures, Ivalage the World-Destroyer Dragon, has finally awakened. These simultaneous crises are completely impossible to predict, yet Tempest's leaders and allies continue fighting, trusting that Rimuru will soon return. However, Ivalage's impending arrival may be closer than they realize...