Due to characters having a long history spanning for years, writers tend to interpret or forget details of a characters. This is most noticable when the characters appears in multiple comics in one month. One major example of this is Deadpool as his reading order is a bit all over the place, and there's no proper segway into the stories he appears in. Apparently in Marvel's earth-616 continuity Deadpool been around since the 70's and 80's era (but, heroes forgot he existed until now.) Was the first person to wear the symbiote suit (which some writers disowned. Personally I think it would be better if he had his own unique symbiote.) For example if you want to read Deadpool in order... (Not counting flashbacks.) Wolverine (1988) #88 Deadpool (1997) #1 Deadpool's Secret Secret Wars (2015) #1-4 Deadpool: Back in Black (2016) #1-5 New Mutants (1983) #98 Deadpool: Circle Chase (1993) #1-4 This mainly happens due to him being the comedic relief of the Marvel universe, and due to his popular status he is able to appear in any story without context, hero or villain. In April 2010 in Earth-616 alone he had 4 ongoing series with no relation to one another. But, hey. I love Deadpool. He has a charm to him! Even if trying to read in order hurts my brain. Wolverine is another example, even if his reading order is less confusing than Deadpool's. Wolverine as of March, 18th 2020, has appeared in 3,111 comics taking place in earth 616 (Probably seconds only to Spider-Man!) In January 2009, he appeared in 24 comics in one month! This is just earth-616 btw. Due to his popularity he's on every team, to the point he mentioned multitasking is one of his mutant abilities. Even if Disney tried to devalue the X-Men brand and killed him off for a good... 4 years, he's back! With a new solo series that launched last month! Wolverine's reading order goes as follows... Origin (2001) #1-6 Origin 2 (2014) #1-5 Marvel Comics Presents: Weapon X (1991) #72-84 The Incredible Hulk (1968) #180 Giant Sized X-Men (1975) Anyone else?