Video game characters are allowed to change. They don't have to stay the exact same forever, either in design or personality. The most effective way to change them is to slowly have the character develop over the course of a game or series. For example, in Red Dead Redemption 2, Arthur can go from being a morally questionable outlaw to a decent human being during the narrative.

However, in several games, characters change a lot more suddenly, as they return in a new instalment with a new personality. Sometimes, this can be explained, and it isn't necessarily a bad thing; it just can be a little jarring. Here are some examples of characters who go through a personality change between games.

In GTA 4, Michelle is a character who pretends to be the girlfriend of the protagonist, Niko. That is until she reveals that she is actually named Karen and is spying on Niko for the Government. So, she is dishonest, but she isn’t presented as a horrible person. She even seems a little remorseful about tricking Niko.

However, in GTA 5, she is an awful human being. She doesn’t get much screen time, but in one scene, she tortures an innocent man to try to get information from him. She does this with the help of a huge flashlight, and she is about to stick it in an uncomfortable place before your characters save the day.

Frank West stars as the protagonist in the first Dead Rising game, which remains one of the series' best. In it, he is a journalist looking for a scoop, but during the game, he slowly becomes a hero and helps a lot of people. Throughout it all, he's a bit sarcastic and witty, but he's generally a grounded character, no matter what goofy outfit you dress him in.

When he returns in Dead Rising 4, though, he isn't quite the same guy. Despite being older, he's actually more immature and cartoonish. Also, he has gotten louder and more obnoxious. It seems to go against the character development he made in the first game.

The first Prototype game stars Alex Mercer. He is an amnesiac protagonist who has incredible supernatural powers. During the game, he and the rest of the Manhattan populace are dealing with a virus that is turning people into mutants. This is how Mercer gained his special abilities.

Deep into the story, Mercer discovers that before he got his powers and lost his memory, he was the one who synthesized the virus and started the outbreak. This mutated version of Mercer is different from the original, though, and he wants to put things right. Therefore, he risks his own well-being to stop the outbreak, proving himself to be a hero. Yet, that change of heart is lost for Prototype 2, as Alex Mercer serves as a pure evil villain in that game.

Albert Wesker is one of the biggest villains in the Resident Evil series. He begins the series as a cunning man able to deceive and outthink most of the people around him. As such, he is able to trick the likes of the elite STARS unit, containing the likes of Chris Redfield and Jill Valentine, into thinking he is their loyal teammate. Plus, he later tricks Umbrella into thinking he's with them.

In Resident Evil 5, though, he has seemingly lost much of his intelligence. He's certainly not the calm and cunning man he used to be. Instead, he is an egotistical madman with a god complex that doesn't seem to outthink anyone anymore. This is likely due to his body being filled with viruses by this point, which may have made him lose his mind.

Fans weren't happy when Metal Gear Solid 2 changed the series' protagonist from Solid Snake to Raiden. Part of the reason is that Raiden in MGS2 is far less cool than Snake. After all, he's a young, naive protagonist who can be overly emotional.

However, he's much cooler when he returns as a secondary character in Metal Gear Solid 4. His personality has changed significantly due to experiencing a lot of trauma between the games. New Raiden is cold, emotionless, and doesn't care if he lives or dies. Yet, he is still committed to protecting others, so he hasn't completely changed.

The Illusive Man is introduced in Mass Effect 2 as the leader of an organization known as Cerberus. The company has a complicated reputation, as it has a history of morally questionable experiments and is not fond of any species that aren’t human. The Illusive Man is similarly complex, and he’s definitely a morally grey character.

From the start of Mass Effect 3, though, he’s pretty much a full-blown villain who’s causing problems and harming innocents. It becomes clear later in the story that he has been indoctrinated by the villainous synthetic race known as The Reapers, which could explain his change in behavior.

The Saints Row games revolve around one of the best groups in gaming, the Third Street Saints. Shaundi debuts in the second game as a member of the crew. She is very laid-back, rarely serious, and is typically on drugs.

The character changes a lot when she returns in Saints Row: The Third. She is no longer presented as a typical mellow stoner. The woman takes things a lot more seriously and doesn't spend much time messing around. Plus, she's stricter and much angrier in the third game. Saints Row itself makes fun of the personality change in the fourth entry, where both versions of the character interact inside a simulation. New Shaundi dislikes the old version of herself, which the game refers to as 'Fun Shaundi.'

Cortana is an AI character from the Halo series who is always by Master Chief’s side, helping save the day. In Halo 4, though, she begins to change. She develops a condition called Rampancy that impacts AI. As a result, she starts to malfunction, and her artificial mind seems to be deteriorating. Therefore, she begins to face her own mortality. At the end of Halo 4, she sacrifices herself for the greater good.

It turns out she isn't gone forever, though, as she's back in Halo 5 as a villain. Using her array of powerful machines, she aims to subdue and control people in an effort to establish enforced peace. The old Cortana was nothing like this.