It's hard to say which is more popular in an absolute sense. The anime has a wider reach in terms of visual media consumers. It can attract those who are more into watching shows rather than reading. However, the light novel has a dedicated fan base among readers who prefer the in - depth exploration of the story that only written works can offer.
Issei Hyoudou is the central character in Highschool DxD. He's a typical horny high schooler at first, but his character evolves throughout the story. Rias Gremory is a significant character as she's the one who gives Issei a new life as a devil. Then there's Akeno Himejima, who has a complex personality and is quite powerful. Koneko Toujou is also important; she has her own backstory and plays an important role in Issei's journey. There are also other characters like Xenovia and Irina who contribute to the story in different ways.
The 'Highschool DxD' light novel and its anime adaptation follow the story of Issei Hyoudou. He is a perverted high school student who gets killed on his first date. However, he is reincarnated as a devil by Rias Gremory. From there, he gets involved in the complex world of devils, angels, and fallen angels. He has to fight battles, make alliances, and also deal with his newfound powers and the harem of girls around him.
Well, the anime 'Highschool DxD Born' is an adaptation of the light novel. The anime brings the story to life with vivid visuals and voice acting. However, the light novel often has more in - depth details, especially when it comes to the characters' inner thoughts and some of the more complex plot elements that might be simplified in the anime for the sake of pacing.
The light novel can contain more content overall. Some side stories or character backstories that are only briefly hinted at in the anime are fully fleshed out in the light novel. Also, the visual aspect of the anime means that sometimes certain interpretations are made that might be different from what readers might imagine while reading the light novel.
If you're someone who likes to imagine the characters and settings on your own, the light novel is a great choice. But if you want to see the action and the characters come to life right away, the anime is the way to go. Also, if you're short on time, the anime can be a quicker way to get into the Highschool DxD world.
Well, the anime often has more visual and auditory impact. It can bring the story to life with cool animations and voice - acting. However, the light novel usually goes into more depth in terms of character thoughts and some detailed plot developments that might be skipped or simplified in the anime. For example, in the light novel, there could be more in - depth exploration of the main character's inner struggle about his new life as a devil, which might be just briefly shown in the anime.