Remus Lupin's death in Harry Potter and the Deathly Hallows was a massive blow, especially since it completely disrupted his overall character arc. This may have been less noticeable in the Harry Potter movies, where Lupin's role in the plot was somewhat reduced. However, much more time was spent developing his character in the books. From the time he was introduced in Harry Potter and the Prisoner of Azkaban, Lupin went through significant growth regarding his courage, but it was all wasted because of his death at the Battle of Hogwarts.
Lupin was added to the Harry Potter movies in Prisoner of Azkaban, where he taught Harry how to produce a Patronus and what it meant to be brave. Later, he met Nymphadora Tonks, and the two fell in love. Over the years, he might have given Harry a little advice, but overall, he had little to do with the central plot of the films. So, when he was revealed to have been killed at the Battle of Hogwarts along with his wife in Deathly Hallows, it was heartbreaking but had minimal further impact. This was not the case in the Harry Potter books, where Lupin's death tragically interrupted years of character development.
Remus Lupin's Harry Potter Arc Was All About Courage & Cowardice
The Harry Potter books had far more to say about Remus Lupin's character. In Prisoner of Azkaban, after teaching Harry to be brave, Lupin confessed that he had been too afraid to tell Albus Dumbledore that Harry Potter's Marauders were Animagi since it would reveal that he and his friends had broken the rules all those years ago. This fear meant that he was knowingly risking Sirius' escape from prison. Thankfully, Sirius ended up being deemed innocent. Still, if Lupin had come clean to Dumbledore, the genius headmaster might have been able to deduce that Peter Pettigrew had faked his death.
Lupin had no problem standing firm in battle to fight for those he loved in Harry Potter, but he was terrified of others' perceptions of him. As a werewolf, he was constantly fearful that people would find out about his condition and that he would be ostracized. As a man, he was terrified of letting anyone down, especially Dumbledore, who had worked hard to get Lupin a place at Hogwarts School as staff (and in the past as a student). So, while he was a brave man in combat, Lupin was a coward when it came to others' opinions.
Lupin Tried To Leave Tonks In The Harry Potter Books
It's unclear exactly how Lupin and Tonks' relationship started. It wasn't until after Dumbledore died in Harry Potter and the Half-Blood Prince that Harry learned that there was anything between them, though he had noticed that Tonks had become glum and withdrawn. As it turned out, this had been because Lupin had put an end to their relationship. He was afraid of how being in love with a werewolf would affect her and how others would perceive them.
Ultimately, Tonks convinced Lupin that she didn't care what others thought, and the two married. However, when Tonks became pregnant, something that was never shown in the Harry Potter movies, Lupin panicked. He was terrified that his child would be affected by his being a werewolf, or at the very least, they would be ostracized for their connection to him. His fear became so powerful that Lupin attempted to leave his wife and unborn son to put himself in danger by joining Harry's mission.
In the Harry Potter and the Deathly Hallows book, when Lupin admitted he regretted marrying Tonks and wished she was not pregnant, he asked his best friend's son if he could join him instead. Enraged, Harry refused, stating he couldn't believe that the man who had taught him how to produce a Patronus was such a coward. He couldn't handle the idea of another orphan like himself, so the Boy Who Lived didn't care if he had to scream and draw his wand on his mentor, so long as the man returned to his wife and child.
Lupin's Movie Character Arc Should Have Ended With His Survival
Lupin stormed out on Harry after their fight in the Harry Potter and the Deathly Hallows book, but he did return to Tonks. Later, Lupin confessed that Harry's instincts were "nearly always right," his way of apologizing and telling Harry that going back to Tonks had been the right decision. When baby Teddy was born, Lupin's fears were swept away. He loved and was fiercely proud of his son, and no amount of fear of what others would think or say was worth missing out on that. Still, in the end, Lupin had to risk his life to ensure his son a better world, and he lost.
Remus Lupin's entire character arc up to the ending of Deathly Hallows revolved around his struggle with courage. It was concluded by his decision to be there for his family rather than put himself in danger. However, his death at the Battle of Hogwarts completely contradicted this. Of course, Lupin had little choice but to fight in the final battle, but surviving the conflict was necessary to satisfy his arc. It no longer mattered that Lupin faced his fear to be there for his family, and Teddy Lupin still wound up an orphan of war in Harry Potter all the same. The werewolf's bravery arc came to nothing.