Can you recommend some good 'dark isekai light novel'?

One popular dark isekai novel is 'Overlord'. It features a powerful protagonist who is transported to a new world and has to navigate through various dark and complex situations. The power dynamics and moral ambiguities in the story make it quite engaging.

Sure. 'Re:Monster' is a great isekai mob light novel. It follows the story of a guy who gets reincarnated as a goblin in another world and uses his wits to become stronger. Another one is 'That Time I Got Reincarnated as a Slime'. The protagonist, Rimuru, starts as a weak slime but gradually builds his own nation in the isekai world.

Well, 'Kumo Desu ga, Nani ka?' (So I'm a Spider, So What?) can be considered in this category to some extent. The main character is reincarnated as a spider in a dungeon. It's different from the typical'mom isekai' as it focuses more on the survival and growth of the spider - girl. But it still has the isekai element where the character has to adapt to a new world. There are also interesting power - up systems and interactions with other creatures in the story.

Well, 'Sword Art Online' can also be considered in a way. Although it's not a pure isekai in the traditional sense as the characters are trapped in a virtual world. But Kirito, the main character, becomes very OP as he progresses through the game world. He has excellent sword skills and adapts quickly to different situations.

Sure. 'That Time I Got Reincarnated as a Slime' is a very popular isekai slime light novel. It has an interesting plot where the protagonist is reincarnated as a slime in another world and gradually builds his own power and kingdom. The character development is great, and the world - building is quite immersive.

One popular 'isekai ntr light novel' is 'The Rising of the Shield Hero'. It has elements of isekai where the main character is transported to another world. Although not strictly pure 'ntr' in the extreme sense, there are some relationship - related plot developments that might be related to the concept.

Another great one could be 'Overlord'. It involves a powerful character being trapped in a game - like isekai world. There are complex relationships and power dynamics that can be considered in the context of ntr elements in a rather unique way as different factions interact.

There's also 'Iori in the Isekai Realm'. In this light novel, Iori discovers unique powers in the isekai world. The novel is known for its detailed world - building, with different kingdoms, races, and a complex magic system. It's a great read for those who like to explore the unknown in a fictional isekai setting.

Well, 'Konosuba: God's Blessing on this Wonderful World!' is also a well - known 'isekai ryouridou light novel'. It has a comical approach to the isekai genre. The main characters are all misfits, and their adventures in the new world are filled with hilarious situations and unexpected twists.

Well, 'Re:Zero − Starting Life in Another World' is highly recommended. It stands out with its unique concept of the protagonist dying and restarting from a certain point in time in the isekai world, which creates a lot of suspense and emotional depth. 'Konosuba: God's Blessing on This Wonderful World!' is also good. It has a great sense of humor and a fun cast of characters as they adventure in the isekai world.