[You did not provide any information about the manga.] If you can provide a specific name or description of the comic, I would be happy to help you determine the source of the comic.
I'm not sure which comic you're referring to. If you can provide more information such as the story of the manga or the author of the manga, I will try my best to help you answer your questions.
Wolverine is from Marvel Comics. They have developed many compelling stories featuring him, showcasing his toughness and complex personality. His presence in the Marvel universe is highly significant and has led to various adaptations in other media.
Well, it's not straightforward to determine. Sometimes Watcher appears in comics, and in other cases, it might be featured in games. It all depends on the creative direction of the particular story or game universe.
Beetlejuice indeed comes from a comic. The comic version provided the foundation for its subsequent adaptations in movies and other mediums. The characters and storylines were first introduced in the comic format.
The 2018 Venom comic is pretty good. It has interesting character developments and some cool action scenes. However, it might not be for everyone. You should give it a read and decide for yourself.