Out of all of the Sailor Guardians that protect the universe of Sailor Moon, the one that went through the most changes from manga to anime by far was Rei Hino, or Sailor Mars. Her mysterious and somewhat reserved personality in the manga was instead change to one of fiery hot-headedness in the anime. While both versions showcase some of the best and worst aspects of the Sailor Guardian, this analysis of her traits will solely focus on her anime counterpart.
Sailor Mars is the second Sailor Guardian to join after Usagi, and she enters incredibly fast when compared to how long it took for Sailor Mercury to join in the original Sailor Moon anime. This is especially true when compounded with the fact that the original English dub cut out several episodes, meaning that her introduction takes place a mere two episodes after Mercury's.
10 Strength: She Possesses A Fiery, Unstoppable Personality
The Sailor Guardians are in desperate need of a stern, driven personality to help get the group in line. That isn't to say that Usagi isn't completely fit to be the leader, as she certainly grows into this role over time, but especially early on in the series, she isn't mentally prepared for the challenge of being a Sailor Guardian.
Rei, on the other hand, tries to call out Jadeite and stop him before she's even awakened to her Sailor Guardian powers. She certainly possesses the unstoppable attitude of a leader that the team desperately lacked when it was just Sailors Mercury and Moon in her early days.
9 Weakness: Her Fiery Side Means She's Quick To Anger
Although Rei's hot-headed personality is great when it comes to taking charge and leading a team, it's incredibly detrimental in the aspect of Rei's personal life. Especially early on when she isn't sure herself if Usagi is capable of leading the Sailor Guardians yet, her fiery nature means that the two are often at odds. Usagi's stubborn, childish nature doesn't calm things between them, and they end up fighting often. This is thankfully something that starts to happen less frequently as she matures, though.
8 Strength: She's A Loyal Team Player Despite Her Independence
Even though Rei might not always agree with Usagi being the leader of the Sailor Guardians, there's no doubt that she still holds a great deal of respect for her. In the Sailor Stars season of the '90s anime, Rei is actually the first person that Usagi talks to when Mamoru still hasn't gotten back to her, showing that they both obviously value each other highly despite having fought often before. And no matter how many times they bicker, Rei is still willing to lay down her own life for Usagi, which is incredibly admirable.
7 Weakness: She Shows Affection In Ways That Hurt Others
Most of the Inner Guardians that are recruited by Usagi haven't had a great string of luck when it comes to making friends. This naturally means that after they do become friends with Usagi and join the group, conflicts are going to arise due to characters not being fully sure how to express their emotions.
In Rei's case, a lot of the teasing that she throws Usagi's way goes a little too far, even if she does respect her deep down. She'd constantly jab at Usagi calling her weak and a crybaby, which were traits she struggled to get over at the time.
6 Strength: She Can Exorcise Evil Spirits Even Without Transforming
Due to Rei's training as a shrine maiden, in the '90s anime, she's able to use one of her trademark powers before she ever gains the power of being a Sailor Guardian. "Evil Spirits Begone" is a cleansing move that allows her to expel evil using a chant and an ofuda, which is a charm said to bear good luck that's typically sold in shrines. While she uses it outside of her Guardian form to dispel evil, it's typically used as Sailor Mars in order to immobilize and enemy and allow her team to finish them off.
5 Weakness: Her Psychic Powers Make It Hard For Her To Connect With Others
Before she connected with Usagi and Ami, Rei was a bit of a lonely child. She had her grandfather and her pet birds, but that can't fully compensate for not forming friendships with others around her age.
Her psychic powers didn't help her case, either, as they caused others to judge her and view her unfairly, shunning her before they'd even really know her. This transferred into Rei handling her friendships poorly at first when she does form them, not knowing how to properly joke with her friends without hurting them on accident.
4 Strength: Her Maiden Training Makes Her An Excellent "Sniper"
It's a trope for shrine maidens in anime to also be adept with a bow, and aside from Sailor Mars, Kagome from Inuyasha and Umi from Love Live are two more notable examples. Although this exact trope isn't something that happened in reality, both demon-breaking arrows are sold at shrines around New Years. They were also given as gifts when a baby was born, along with a decorative bow that's said to ward off evil.
Rei is able to use her bow skills as Sailor Mars in the form of her "Mars Flame Sniper" attack. It's an incredibly powerful and precise attack, capable of burning its target to ashes.
3 Weakness: She Can Be Unnecessarily Defensive
Going along with Rei's tendency to become heated and pick fights with Usagi often, she can also be incredibly defensive. This is first seen as early as whenever Usagi firsts visits the Hikawa Shrine, as visitors are accusing the shrine of being responsible for the missing people incidents.
Although it's understandable why she does, Rei immediately loses her temper and shouts at them. For someone who was already under suspicion, regardless of how false, her quickly-defensive attitude certainly doesn't help draw suspicion away from her.
2 Strength: Her Powers Can Forewarn Her Of Evil
Rei's powers of premonition are the only other power aside from her evil expelling move that she possessed even before becoming a Sailor Guardian. These premonitions, typically seen either in her dreams or within flames, can warn her about dangers in the near future.
She was able to use this to realize that Jadeite was the enemy disrupting her readings but was captured afterwards, then awakening to her power as Sailor Mars. The only thing that stops this power from being incredibly overpowered is the simple fact that it isn't always accurate.
1 Weakness: She Can Be Selfish When It Comes To Love
In the classic anime, Rei and Mamoru have a small fling where they're romantically involved, and it really shows just how detrimental Rei's boy-crazy side can be at times. Mamoru was never really into Rei, and even someone like Usagi before recovering her memories, was able to see that. However, Rei was so obsessed with having the person she pictured as her ideal partner with her that she never noticed. It was clear from the very beginning that Usagi had a crush on Mamoru as well, and Rei still decided to pursue him anyway. It's the part of her character that fans — especially those who are familiar with her colder, male-rejecting side in the manga — aren't fond of.