Weak characters have their place in television shows. They provide a base comparison for the competent and powerful characters to be measured against. They can act as somebody who needs defending by the more powerful characters to create emotional ties, and they can have other skills essential to the plot without coming off as "overpowered" by comparison. Their weakness can even be played for comedy.
Sometimes, a character who is initially weak becomes much stronger over the course of the show. Whether it be because they gain superpowers, develop new skills, or simply go through character development that makes them much more dangerous, some of the most powerful characters in TV had meek beginnings.
10 Walter White Started As A Scared Chemistry Teacher (Breaking Bad)
Walter White, in his 'Heisenberg' persona, is one of the most terrifying villains of recent television by the end of Breaking Bad, with him being the protagonist not doing much to dull just how evil and dangerous he can be.
In early episodes of the show, despite occasional moments of courage like using explosive chemicals to intimidate a gang of drug dealers, Walter is very much out of place in the criminal underworld, weak and easily threatened by hardened criminals. By the end of the show, he orchestrates mass assassinations in high-security prisons and takes on a gang of Neo-Nazis singlehandedly.
9 Willow Gained Powerful Magic (Buffy the Vampire Slayer)
In early seasons of Buffy the Vampire Slayer, Willow is the weakest member of the group. She lacks the supernatural prowess of Buffy and Angel, the skills of Giles, and even Xander's occasional victories in battle. Instead, she's the smart member of the group, applying her intelligence to technology and to research to aid her friends.
Starting in Season 2, and coming into her stride in Seasons 3 and 4, Willow begins to learn magic and reveals herself to be one of the most powerful witches in the show. In Season 5, she is able to hold her own against the near-unstoppable Glory for a time, and in Season 6 comes very close to ending the world.
8 Lionel Fusco Stopped Needing To Be Protected (Person of Interest)
Lionel Fusco's use in early seasons of Person of Interest begins and ends at being a reluctant and corrupt ally to Team Machine, who can help them when legitimate law enforcement cannot. Many times, he would need Reese and the others to save his life when he got in too deep.
Fusco begins to show signs of competence as early as the first season finale, but it is in later seasons he really proves how strong he has become, winning fights against gangs of hitmen and disarming bombs at short notice.
7 Carol Peletier Kills More Than Zombies (The Walking Dead)
Carol in The Walking Dead appears in the show from the very first season, but initially, she is not of much help to the gang. Meek and terrified of her abusive husband, the only times Carol shows any steel is when her daughter is involved.
After seasons of character development, Carol becomes one of the most dangerous characters in the show. Aside from her skills with weapons increasing drastically, she has notably hardened and become bolder, and shows a willingness to do things she would have previously seen as unthinkable.
6 Jackson Becomes The Kanima (Teen Wolf)
Jackson Whittemore begins Teen Wolf as a stereotypical horror movie jerk jock, a rich kid who enjoys pushing around the protagonists, despite showing some hidden depths. Despite his athleticism, he is badly in danger any time he is caught up in the supernatural intrigue of the first season, needing protagonist Scott McCall to save him.
At the end of Season 1, Jackson is bitten by Alpha Derek, and becomes the Kanima, a nearly-indestructible shapeshifter who exists to wreak vengeance, and the most pressing physical threat any of the characters have faced to that point. When he returns in Season 6, he is half-Werewolf and half-Kanima, able to mix both halves to be an even greater combatant.
5 Morgana Turns Into Merlin's Great Nemesis (merlin)
In Merlin, Morgana is far from incapable in the series's beginning, able to handle a sword well enough to protect herself, confident, and unafraid to use her influence to help Merlin and Arthur. Nonetheless, she lacks the combat skill of Arthur and the Knights of Camelot, and at that point, can't use magic like Merlin can.
As she turns evil, Morgana becomes a more and more competent sorceress, learning from the deadly Morgause. By the end of the series, she is almost as capable as Merlin, who is the greatest sorcerer to ever live.
4 River Tam Realises Her True Potential (firefly)
River Tam spends much of Firefly as equal parts plot device and character, being a mentally unstable young woman who needs hiding from the Alliance due to her past. As the show goes on, it is revealed that this past involves being operated on to enhance her psychic powers and to turn her into a deadly soldier.
While some hints of this power reveal themselves over the course of the series, it is only in Serenity that River overcomes many of the mental blocks stopping her effectiveness and embraces her true power, fighting dozens of Reavers at once.
3 Mickey Spends Time With The Preachers (Doctor Who)
When Mickey Smith is first introduced in the revival of Doctor Who, he is simply Rose Tyler's hapless boyfriend who frequently comes out worse for wear as a result of the cast's adventures. He is swallowed by a bin, taken prisoner by clockwork robots, and investigated by the police, and most of the cast laugh at him or fail to treat him with respect.
In Season 2, Mickey replaces his alternate-universe counterpart, Ricky, with the resistance group The Preachers. When he returns, he is a capable warrior who takes part in pitched battles between Daleks and Cybermen, and ultimately goes on to become a mercenary protecting the Earth.
2 Wesley Becomes The Most Dangerous Member Of Team Angel (Angel)
In both his introduction in Buffy, and his early time on Angel, Wesley is a character played for comic relief. Whether he's dressed in a suit and nervously stammering, or riding a motorcycle and claiming to be a 'rogue demon hunter,' he is often on the losing end of fights, and outcompeted by others on his team.
Gradually on Angel, however, Wesley becomes more and more dangerous. He gains courage, standing up to other Watchers and his father, becomes one of the team's most lethal members with a sword, and develops a talent for sorcery. He also becomes far more ruthless and prone to shooting first, until he is the worst member of the team to cross.
1 Arya Stark Saves The World (Game of Thrones)
Arya Stark is never lacking for ferocity at any point in Game of Thrones, showing considerable talent as an archer from the off and yearning for a life of fighting and adventure. Despite this, she is only a young girl at the beginning, and as a result is unable to fight against the many dangers threatening her, often having to run away from situations.
In the next few seasons, Arya learns from The Hound, the Faceless Men, and Brienne of Tarth, developing a terrifying and lethal array of skills that make her the equal of nearly anybody in combat. The best demonstration of how far she's come is that she slays the Night King during the Battle of Winterfell, a terror who has haunted Westeros for generations.