Isekai manhwa refers to Korean comics where characters find themselves in otherworldly or parallel dimensions. It's a popular genre that offers exciting and imaginative storylines. Sometimes the characters gain special powers or have to overcome various challenges in these strange new worlds.
One characteristic of completed isekai novels is the concept of the 'fish out of water' scenario. The protagonist is suddenly in a new and strange place, like in 'Konosuba'. They also often have elements of adventure and discovery. The main character has to explore the new world, find resources, and face various challenges. Additionally, many completed isekai novels play with the idea of changing the new world according to the protagonist's will, as seen in 'The Rising of the Shield Hero' where the hero tries to reform the unjust world he's in.
One great completed isekai novel is 'That Time I Got Reincarnated as a Slime'. It follows the story of a man who is reincarnated as a slime in a fantasy world and builds his own nation. Another is 'Overlord'. In this novel, a powerful player gets trapped in the game world and begins his conquest. Also, 'Sword Art Online' has some isekai - like elements in its story, where players are trapped in a virtual world.