Definitely. Yu-Gi-Oh began as a manga series and its success led to the creation of other related media such as the anime and the card game. The manga laid the foundation for the entire franchise.
The Yu-Gi-Oh! ZEXAL YAOI manga has its unique style and storyline. It stands out with its focus on certain themes and character relationships that might differ from other Yu-Gi-Oh! manga.
Sure. For example, there might be variations based on different creative teams or targeted at different audiences, resulting in two separate Yu Gi Oh manga.