Since I haven't read Konosuba volume 17, I can't say for sure. However, in previous volumes, new characters were often introduced to add more variety to the story. They could be allies or antagonists. In volume 17, new characters might be from a different part of the world in the Konosuba universe, like a powerful wizard from a far - off land or a sneaky thief from a seedy underworld.
I'm not entirely sure without re - reading it specifically, but there may be some minor characters introduced to add more flavor to the story, such as local villagers or new adventurers in the area.
In volume 5, one of the main plot points is the group's encounter with new challenges in the fantasy world. They might face stronger enemies or difficult quests.
I'm sorry, I haven't read Konosuba volume 14 web novel specifically, so I can't accurately state the main events. But generally, it might continue the adventures of the main characters in the strange fantasy world, with new challenges, battles against monsters, and some comical interactions among the group.