First, you need to have a deep understanding of the original work's characters and world. Then, come up with an interesting plot that fits within that framework.
Overall, the ending of the manga was well-structured. It tied up loose ends and left fans feeling content. The resolution of conflicts and character developments were handled smoothly.
The 'How Not to Summon a Demon Lord' manga did finish. It provided a satisfying ending that tied up loose ends for fans. The final chapters brought closure to the characters' adventures.