Some might consider 'In Another World with My Smartphone' as one of the worst. The plot is quite predictable. The protagonist gets overpowered abilities just because he has a smartphone in the other world, and there's not much depth to the story. It seems more like a series of random events centered around showing off his abilities.
One of the worst might be 'In Another World with My Smartphone'. The plot is overly simplistic and full of clichés. The main character gets OP (overpowered) abilities too easily and the harem aspect is just thrown in without much depth.
Poor character development is another reason. In some isekai novels, the characters are just one - dimensional. They don't grow or change in any meaningful way throughout the story. Like in certain novels where the protagonist is just a self - insert for the reader to live out a power fantasy without any real personality. And the world - building can be really shoddy too. They might create a fantasy world but not really explore its rules, cultures, or history in a way that makes it feel real and immersive.
This question was not easy to answer because the quality and evaluation of the male lead in the anime depended on many factors such as the plot, character creation, audience preferences, and so on. Moreover, the definition of "the most scum" varied from person to person.
However, if it was referring to the performance of the male lead in a certain anime, then it could be said that every character had its own unique charm and value. It was difficult to simply rate a character as the "worst".
Some isekai light novels are considered the worst because they lack originality. For example, many follow the same pattern of a normal person being transported to a fantasy world and suddenly becoming very powerful. There's no real innovation in the story setup.
One popular isekai anime story is 'Sword Art Online'. It's about a virtual reality MMORPG where players get trapped in the game world. Another is 'Re:Zero - Starting Life in Another World', which follows Subaru as he is transported to a fantasy world and has the ability to return by death. 'That Time I Got Reincarnated as a Slime' is also well - liked, where a man is reincarnated as a slime in a different world and builds his own kingdom.
In my opinion, 'High School DxD' had some issues as an anime adaptation of a light novel. While it was popular for its fanservice, it deviated quite a bit from the original light novel in terms of story and character growth in the later seasons. The story started to feel more like an excuse to show off the female characters' bodies rather than focusing on the plot and character development that was in the light novel.
One great isekai anime based on a light novel is 'Re:Zero - Starting Life in Another World'. The story follows Subaru Natsuki, who is suddenly transported to a fantasy world. The light novel provides a rich source material, and the anime adaptation does an excellent job of bringing the complex characters and the thrilling plot to life, especially with Subaru's unique ability to return by death.
Some popular ones include 'Sword Art Online'. It's set in a virtual world where the protagonist is trapped, and it has elements of isekai as the virtual world is a different kind of realm. Another is 'Re:Zero − Starting Life in Another World'. The story follows Subaru who is transported to a fantasy world and has to face numerous challenges and deaths, with his unique ability to return by death.
Isekai anime stories often offer a sense of power and growth. The main characters usually start from scratch in the new world and gradually become powerful. For example, in 'That Time I Got Reincarnated as a Slime', the protagonist evolves from a simple slime into a powerful being. Also, the unique settings in isekai anime, like the various magic systems and strange creatures, are very attractive.