Since birth, Harry Potter had been destined to be the downfall of Lord Voldemort. Even though his first defeat of Voldemort occurred because Lily Potter's love for Harry was so strong that the Avada Kedavra curse backfired, Harry had since been labeled as a symbol against dark magic and its users. This association continued on through Harry's schooling as he essentially faced off with some iteration of Voldemort each year and won each time. As the Second Wizarding War arose, talk of Harry and Voldemort facing off once again arose in the Wizarding World.
On top of this, Harry excelled in his Defence Against the Dark Arts classes, scoring high on his Ordinary Wizard Levels (O.W.L.s) and even teaching other students how to defend themselves when their teacher that year refused to do so. Harry ultimately became an Auror, but he would have done well as a Professor at Hogwarts. Here is a look at five reasons he must have made a great Auror, and five reasons he should have been the next Defence Against the Dark Arts teacher.
Auror: He Wanted To Be An Auror
When preparing for the O.W.L.s during his fifth year, Harry expressed to Professor McGonagall his desire to become an Auror, likely because of his motivation to protect his loved ones as well as utilize his talents for defensive magic. He was even willing to suffer through Potions classes for two more years at the prospect of becoming an Auror.
He was able to gain an exception for never attending his seventh year at Hogwarts and was allowed, alongside Ron and Neville for a time, to join the ranks of the Aurors.
DADA: His Quiet Charisma
Harry was more introverted in personality, preferring to keep a low profile rather than draw attention to himself. Furthermore, he was an average student in every area except Defence Against the Dark Arts, at which he excelled, and Potions, at which he struggled.
In spite of these traits, students and faculty alike generally liked Harry. Obviously he wasn't liked by everyone because that's impossible. However, the fact that people were still able to like him as a person shows that he would be a charismatic teacher, had he chosen to go that route.
Auror: He Didn't Like Academics
As mentioned above, Harry was a fairly average student with the exceptions of his varying performances in Defence Against the Dark Arts and Potions. Furthermore, he often complained alongside Ron about the homework he received and tried to convince Hermione to do his homework for him, if not help him complete it.
While it is not explicitly stated in the books, Harry's attitude toward classes and homework implies that he does not like academics or studying. This is further implied by the fact that he, unlike Hermione, never went back to Hogwarts to finish school. If he didn't like being in school as a student, it is unlikely he would enjoy teaching. It is clear he preferred real-world experiences, meaning he would have enjoyed that aspect of being an Auror.
DADA: His Use Of Expelliarmus
By Harry Potter and the Deathly Hallows, the Disarming Charm, also known as Expelliarmus, had become Harry's go-to spell in dueling and thusly was considered his signature move. Harry used it so much that Death Eaters were able to identify him among six other people disguised as him through the use of the Polyjuice Potion because he used the spell.
Harry's philosophy was that he did not actually want to harm or kill anyone and thusly chose to disarm them, which would be a useful philosophy to pass on to younger generations of witches and wizards.
Auror: He Considered One Of His Strengths To Be Flying
When he competed in the Triwizard Tournament and was coming up with a strategy for battling a dragon, Professor Moody asked Harry what he considered his strengths to be. Harry replied that he could fly a broom. This means that on top of actually being an average student, he did not think highly of his skills in academics and thought he was better off with practical approaches.
Practicality would serve him better as an Auror than it would as Defence Against the Dark Arts Professor. Furthermore, his views on his academic performance may imply that he would become a Flying Instructor or Quidditch Coach at Hogwarts before teaching Defence Against the Dark Arts.
DADA: His Strong Patronus
Harry was able to produce a fully formed Patronus by the end of his third year at Hogwarts. Since then, he used it several times throughout the series to defend himself and his friends and to teach it to members of Dumbledore's Army.
The Patronus charm on its own is an incredibly advanced spell, especially a fully formed one. The fact that he was able to produce it and later teach it to other students of varying skill levels shows that he has a knack for teaching that not everyone is lucky to have.
Auror: He Got An "Outstanding" On His DADA O.W.L.
The summer before Harry's sixth year, he and his friends received their results from their O.W.L. exams. Harry received one score of "Outstanding" in Defence Against the Dark Arts, something that even Hermione had not achieved. His high score is a testament to his skill and aptitude for defensive spells, something that Professor Tofty, who oversaw three of Harry's O.W.L.s, immediately noticed during the examinations.
In order to become an Auror, prospective candidates need to score an "Exceeds Expectations" or "Outstanding" in their N.E.W.T. classes. Since Harry received an "O" during the O.W.L.s, it is highly likely that he would have received the same grade for the N.E.W.T.s had he continued on to his seventh year.
DADA: Dumbledore's Army
While Professor Umbridge taught Defence Against the Dark Arts during Harry's fifth year, she refused to teach actual defensive and offensive spells in favor of the theory of defensive spells instead. Harry and other Hogwarts students wished to learn actual magic, so Harry, with help from Hermione, put together Dumbledore's Army where Harry taught all students willing to learn actual defensive magic.
Up until the group's sudden disbanding upon being found out by Umbridge, Harry successfully taught students of all skill levels different types of defensive magic, from Patronus charms to Stunning spells.
Auror: His Real-Life Experience
From age eleven, Harry started acquiring real-life experience in defending himself against dark magic and its users. He fought Voldemort multiple times, destroyed Horcruxes, and fought magical creatures such as Dementors and dragons. He even developed a resistance to the Imperius Curse, something that is particularly difficult for even the most skilled witches and wizards to master.
Since Harry began using defensive magic at such a young age, he gained a lot of experience and was able to develop his skills before taking the first steps to become an Auror, meaning he is likely more qualified than most people vying for the same job.
DADA: His Love Of Hogwarts
After spending ten years being abused in various ways by the Dursleys, Harry was able to find a home at Hogwarts. Because of this, he stayed at Hogwarts during school breaks when he could, and often spent his summers looking forward to being back at Hogwarts.
Hogwarts was the first place at which Harry truly felt at home. This love for the school would have served him well as the Defence Against the Dark Arts professor. He would be working with a type of magic he excelled at while working in a place where he truly liked to be.