Shadow Realm
The Shadow Realm, in the English-language version of the Yu-Gi-Oh! anime, is a place of eternal suffering where people can be sent to.
The Shadow Realm does not exist in the Yu-Gi-Oh! manga and the original Japanese anime. 4Kids Entertainment, the producer of the English anime, added in the Shadow Realm. The "Shadow Realm" was often used to write out the real possibility of death or to write out the death of the character; for instance, Marik Ishtar's father was sent to the Shadow Realm in the English anime while in the original Japanese anime and the manga, Malik Ishtar's father was killed with a dagger.
Some characters are pulled out of the Shadow Realm in the English anime and the English-language video games.
