While it isn't the most successful of the Marvel franchises, the X-Men franchise is most certainly the oldest, with the first movie being released in 2000. Since then, the fans have seen five X-Men movies, plus two spinoffs focused on Wolverine, who was already the star of the ensemble flicks.

And since this shared universe is not watertight (just like the MCU attempts to be), there are quite a few inconsistencies in the continuity, especially between the original and the second trilogies. And this wouldn't be so bad if X-Men: Days of Future Past hadn’t tried to erase the timeline completely - it did try, but it failed, and it raised even more questions.

Well, after two weeks in the US, these continuity conundrums may have had the last word, since poor word-of-mouth is based especially on the fact that the movies, at this point, make no sense. And it appears that the blockbuster X-Men: Apocalypse was supposed to be will actually be a flop in the US (just $122 million in two weeks).

So, what is driving this franchise into the ground? Here is a list of the most annoying continuity errors, from the first X-Men movie through the last.

As always, here be spoilers!

Nobody ages

This one is the biggest of the lot so it should open the list - ever since the new trilogy began, none of the X-Men members, nor any of the human supporting characters, seems to age. This can be explained for characters such as Mystique, who is a shapeshifter, meaning that she can choose to look younger; or Wolverine, who possesses an off the charts regeneration ability (but still looks older than he did in 2000). But what about all the other mutants? Do they also possess this kind of ability, as well?

It’s even weirder with the human characters - for example, Moira MacTaggert doesn't age a bit in two decades, a detail noted by Professor X as well.

And the blame for this rests on Bryan Singer, who’s the one who decided to set each of the movies – after First Class - in different decades. Why? Well, I have no idea why he went this route. But something needs to change, and it needs to change before the next X-Men movie arrives.

Don't set it in the "˜90's.

But hey! The characters don't age in the comics, either. So maybe this is the most plausible explanation.

A cure for all mutants

The Last Stand was all about a cure being found for the mutants - they don't need to be outcasts when they can become human. With all its flaws, Last Stand could have been a great statement on this issue when applied to the real world and all the prejudices that exist in it.

But it wasn't.

In the movie, it is said that the first cure for the X-gene has been discovered. But is that really the first? I can't say that this one is all Bret Ratner's fault, since First Class and Days of Future Past arrived afterwards. Thus, Hank McCoy was the first one to come up with such a cure during First Class (it backfired, but still), only to perfect it in Days of Future Past, effectively curing Professor X of his ability to read minds. So what gives? Which one was first? And why is Beast so surprised in The Last Stand when he finds out about this cure?

Some things will never be explained.

Of course, Days of Future Past may have tried to fix this, deleting what happened in the Bret Ratner flick. But the time-travel doesn't explain why the 2006 Beast was so surprised, when he did it himself in the "˜70's and then in the "˜80's, well before Wolverine time-jumped.

Emma, Jubilee, Psylocke, and all the others

This is another issue I can't get my head around - if the original movies (the first Wolverine included) present some mutants as adults (or in their late teens), why do the follow-ups dismiss these details?

Such is the case of Emma Frost, one of the most powerful telepaths in the comics. The problem is that she appeared in the first Wolverine flick as being in her late teens, only to appear in First Class (which is set quite some time earlier) as an adult.

The same goes for Quicksilver (who only cameoed in the first Wolverine flick), as well as some of the other mutants.

And then there’s Psylocke, who also appeared in Last Stand before Apocalypse. And the same issue applies, with another one added to the mix - the change of superpowers. In the comics (as well as in X-Men: Apocalypse), she is a powerful telepath with extraordinary telekinetic abilities, but in Last Stand she is a teleporter. Bend your mind around that.

It can be explained, of course, since many times in the comics the characters get upgrades. But still - these aren't the comics, and a bit of continuity wouldn't hurt.

The death of Professor X

Professor X is completely dematerialized by Jean Grey in the Last Stand. But it was nothing more than a scratch, since he is revealed to be alive (in some way) in the credits scene, transported in what seems to be a different body.

To add insult to injury, Moira is now (that's 2006, in the timeline) an MD, which completely contradicts her history (as revealed in the second trilogy) as a CIA agent. Of course she looks very young and she knows who Charles is.

To be clear, his body wasn't cloned - so how does he get it back for Days of Future Past? Furthermore, it cannot be explained how he manages to transfer his mind into a different body, god knows where, since this isn't one of his abilities in the movies.

Sometimes it just doesn't make sense. And this credits-reveal only confused those who watched The Last Stand. Now, if Days of Future Past didn't bring back the Patrick Stewart Xavier, it wouldn't have raised so many questions - but it did.

Professor X and Magneto's history

This is yet another big issue with the X-Men movies, because these two have been central characters of the franchise from the very beginning. And if their history made sense in the first trilogy, it was completely nonsensical once First Class arrived.

Thus, in the first movies, Charles explicitly said that he met Erik when he was in his late teens and that they have been friends for a while - as revealed in Last Stand, they were friends until their forties or even beyond.

First Class throws this overboard, since they are both adults at their first meeting, when Erik is searching for those responsible for his mother’s death. First Class was an excellent movie as far as I am concerned, with Fassbender's performance being one of the best I've ever seen in comic book movies.

However, these small details diminish what Matthew Vaughn achieved. Of course, Bryan Singer later acknowledged it was a mistake to write the line concerning the meeting between the two. But does that make up for it? No, it doesn't.

Mystique and Professor X's history

Mystique is the character most of the fans want gone, and that is because of the inconsistencies concerning the character within the second trilogy. Mutant and proud? A hero? Jennifer Lawrence shoeing it in?

However, there is a bigger problem when the first trilogy is connected with the second one - she and Professor X were as close as if they were brother and sister! And that is not addressed in any way in the original trilogy. If Charles can say that he and Erik have a history together, why can’t he acknowledge that he and Mystique also share a past?!?

And this is one of the biggest problems of them all - I cannot see this version of Mystique, after three movies, doing her best to kill the professor, as she did in the first three movies. I just can't. And I can't blame it all on the whole history has changed thing - after all, First Class features a cameo of the original Mystique, thus connecting the two trilogies to an even greater extent.

And if Mystique and Magneto have been friends for so long, why does he cast her away as soon as her powers are stripped in Last Stand?!?

Sabretooth

Moving a bit away from the second trilogy, we find Sabretooth. He was the huge dumb beast sent to retrieve Rogue, thus putting the plot of the first movie in motion, with Wolverine at its core. And then came the first Origins movie, where it is revealed that Sabretooth and Wolverine are brothers - and the fact that the villain (who, for some reason, barely speaks in the X-Men movie) doesn't recognize his brother, as well as the decade-long hatred between them, it is mind boggling.

Furthermore, the character is completely changed. If in the Origins movie he is actually quite talkative and is depicted as being an intelligent person (one who might actually come up with a plan on his own), the X-Men movie reduces him to a mere pawn. And that is all - as said, he is just a huge dumb beast.

I guess this is what happens when you don't believe that a franchise will pick up, as the X-Men did: you cast someone big as Tyler Mane, without thinking that maybe, at some point, you'd require someone with actual acting chops.

First Class - not really

The first X-Men movies make a big deal of the fact that the first X-Men seen are also the first students the professor has taught. There is actually a scene in the first movie where Professor X clearly and explicitly says that Cyclops, Jean, and Storm are the first students he ever had.

If we jump to the Origins spin-off, there is no problem - the problem appears starting with First Class, where the first students cannot be more different than those 3 mentioned above. Yeah, there is Havok, who is Cyclops’ brother, but still"¦

Even Mystique, who is a certified villain in the first trilogy, is one of his first students. So what gives? Did someone erase Xavier's memory, like he did (unnecessarily) with Moira?

Wolverine's mind-bending history

There are tons of inconsistencies with this character alone - but I'll choose the most obvious one: how he got his adamantium claws in the most recent iteration of the character. I'll leave aside the ending of The Wolverine, I'll leave aside the whole Origins thing, and so on.

Thus, in the end of Days of Future Past, he is pulled out of the Potomac by Mystique disguised as Stryker. Still, in Apocalypse, it is revealed that he was actually captured by Stryker, brainwashed, and transformed into the Weapon X. And while this is a better origin story than the other one, it still has a huge question mark hovering over it.

Of course, we can assume that it was another shapeshifter who captured him. But why would I do that? Thus far, in the movie, only Mystique has this ability. And while Mister Sinister will certainly appear, it still makes no sense.

Unless Sinister's origin is also tampered with, and he isn't a creation of Apocalypse, as he is in the comics.

Deadpool

Even Deadpool makes fun of Origins. In other words, Fox laughs at what it came up with in 2009. In other words, Fox laughs at the fans' expense. And this is not nice at all.

Deadpool's history was retconned. And so was Wolverine's. But what was the result, besides some jokes made by the former? Maybe Fox should plan ahead and stick more to what’s in the comics.

And that's about all as far as Deadpool is concerned - from this point of view, it was a bad joke that turned into a pretty good one.

Cerebro

In Bryan Singer's X-Men movies, Cerebro plays an important part each and every time. So you can bet that someone screwed this one up as well. In this case, it is Matthew Vaughn in First Class.

In the original trilogy, Xavier says that he built Cerebro with Magneto's help. Which is understandable, since someone had to do the heavy-lifting. But I understood that Professor X came up with the plan for a machine which would enhance his telepathic abilities.

Well, First Class says otherwise. In the sense that none of them came up with the plan. Instead, it was Hank McCoy who did it, all by himself. Apparently, Professor X is quite a liar. But it is actually Fox who doesn't give a rat's tail about continuity.

I wonder who will direct the next X-Men movie, and how they'll retcon everything included (or not) on this list.

Lastly"¦

X-Men - a rock-hard reboot

The biggest continuity problems in the X-Men franchise (and they aren't all stated here, just the biggest ones) come from one idea only - that the two trilogies we've seen so far should be tied one to another. In other words, the biggest problem is that First Class was released as a soft-reboot, one that would erase only the bads of the previous movies (and these were Last Stand and Origins). In doing so, tons of things don't add up right now.

I don't have a problem with Singer directing, although his announcement about leaving the X-Men franchise (but staying as a producer) brought a smile on my face. The biggest problem I have is that Fox doesn't plan ahead. Like Marvel does - and no, I'm not one of those who believe that the X-Men should come back to Marvel, simply because there will be no X-Men afterwards, since Marvel has already planned ahead until 2028.

So, what Fox should do is a hard reboot, as it should have with First Class. Cast away the young versions of the old mutants (Sophie Turner is a terrible actress anyway) and bring in new mutants. It isn't as if the X-Men comics featured just this core.

What do you think? What other huge continuity mistakes have you found in the X-Men franchise? And shouldn't Fox consider a hard reboot?