That Time I Got Reincarnated as a Slime (Volume 20)

Although Rimuru managed to defeat his archenemy Michael, battles continue raging across the land, and the fighting between Milim’s forces and the insectors is particularly chaotic. Just when the outcome seems to be in Milim’s favor, a beautiful woman of ice and snow appears, drastically shifting the tides of the war. She is none other than Velzard, the eldest of the three True Dragons left in existence. Once Velzard overwhelms the situation, encasing everything in ice, Milim begins to rampage—and Rimuru has no choice but to return to the battlefield to stop her!