Courage helps classify Attack on Titan characters into two categories - those who fight their fears and those who give in to their monsters, inner or otherwise. The latter can't, and shouldn't, be judged for the decisions they make, because the tumultuous world they inhabit doesn't care much about morality, integrity, or even common courtesy.
However, this doesn't mean that everyone in the story is as capricious and self-serving as the worst of humanity. Bravery appears in a variety of forms in Attack on Titan, ranging from emotional to physical and everything in between, but all versions of courage can be considered essentially the same for narrative purposes.
Manga Spoilers Below
10 Eren Chooses To Subdue The World With Terrorism
Eren Jaeger isn't exactly a coward, but the path he walks down is soaked in blood and suffering, something no true hero is capable of inflicting on anyone, let alone the people they love. Unable to find an acceptable solution to the Titan problem, Eren chooses to subdue everyone by terrorizing them into compliance.
His actions help preserve the safety of Paradis but almost certainly put his nation in the crosshairs of the entire world. In his defense, however, Eren acknowledges his incomplete vision and attempts to make amends before his death.
9 Bertholdt Doesn't Always Practice The Composure He Preaches
Bertholdt demonstrates the power of composure during his stint with the Scout Regiment, impressing both peers and supervisors with his common sense. He's the first person to reassure Reiner when the latter spirals into one of his trademark identity crises, insisting that a clear head is the first step to transcending one's fears.
Unfortunately, Bertholdt doesn't always practice what he preaches. When he's about to be eaten by Armin's Pure Titan, he writhes and screeches in fear before begging Annie and Reiner to save him from his doom.
8 Reiner's Bravery Is Meaningless Without The Willpower To Back It Up
Reiner's mental state develops more cracks every time he commits an atrocity against his Scout friends, which ironically illustrates his nobility of character. The only problem is that Reiner's virtues are buried deep within his unconscious mind, which is why he accepts his role as a Warrior despite his internal conflicts.
He understands that his people would never be anything more than a lower class in the eyes of Marley, and yet, this doesn't stop him from trying his hardest to obtain a peaceful life for his family. Reiner's bravery is evident, but it is meaningless without the willpower to back it up.
7 Porco's Audacity Is All The More Evident When He Faces Certain Death
While Porco Galliard reeks of a superiority complex when it comes to his control over the Jaw Titan, his accomplishments reveal him to be an experienced Warrior with a knack for combat.
His battle with Eren's Attack Titan shows just how far Porco is willing to stretch his limits, even if it means losing his limbs in the process. Porco's pride is partly responsible for his downfall, but nobody can deny the young man's sheer audacity in the face of certain death.
6 Levi's Nerves Are Forged From Ultrahard Steel
Levi Ackermann's indifferent nature is a result of his upbringing. His uncle Kenny raises him for a brief period before abandoning the young boy to his devices.
Regardless of his external frostiness, Levi cherishes his squad deeply, which explains his pained expression upon hearing of their deaths. His strength, dexterity, and swordsmanship are so advanced that they might as well be magic, but none of them would have any value if not for his nerves of ultrahard steel.
5 Hange Sacrifices Themselves So That Others May Live
Hange Zoë's playful charm gradually lessens throughout the series, but their intelligence and rationality remain as impactful as ever. They find no shame in admitting their weaknesses, especially their fears of the unknown, which is what makes Hange such a courageous character in the first place.
They distract the Rumbling Colossal Titans at the cost of their life, satisfied in the knowledge that their friends would take care of the rest. Hange's sacrifice is one of the most profound moments in Attack on Titan.
4 Armin's Bravery Shines Brightest When He Fights His Closest Friends
Armin might love Eren more than anyone else in the world, but his love for the world trumps his personal feelings. Unlike Eren, who destroys humanity in order to save a tiny fraction of the global population, Armin refuses to consider death as an option (as long as it can be logistically avoided).
Armin's bravery especially shines during moments of conflict with his closest allies, proving, like Neville Longbottom in Harry Potter, that one needs "just as much [bravery] to stand up to our friends."
3 Gabi's Self-Conviction Allows Her To Perform Near-Miraculous Acts Of Boldness
Gabi Braun's excessive belligerence is quite irritating to those around her, pushing her superior's buttons with her inability to follow orders. As the poster child for Marley's anti-Eldian indoctrination, Gabi spouts incoherent arguments in support of her decisions, shutting down anyone who dares to deny her version of the truth.
At the same time, Gabi's conviction is so powerful that it leads her to perform near-miraculous acts of audacity, from killing Sasha Braus to "executing" Eren Jaeger.
2 Erwin's Courage Does Not Wane For Anything Or Anyone
Erwin Smith is intelligent, shrewd, and always has a contingency plan (or ten) for any given situation. Under his leadership, the Scout Regiment becomes one of the most powerful military/political entities in Paradis.
It can be argued that Erwin's careful planning paves the way for the story's conclusion, but his boldness is easily his most notable feature. When a Titan snaps him up in its mouth, Erwin doesn't scream in pain or beg for his life. He instead unleashes inspirational war cries to encourage his nervous subordinates.
1 Mikasa Ackermann Completes The Most Terrifying Mission Of All
From the introduction, Mikasa is represented as Eren's best friend/personal bodyguard, a dual role that she fulfills to the best of her ability. Although the source of her love for Eren remains unclear, the fact that Mikasa agrees to kill him at the end of the story is evidence of her adamantine grit.
Taking Eren's life is her final test, and it also helps Ymir Fritz achieve closure after 18 centuries of psychological agony. That said, Eren will always remain a part of Mikasa's heart and soul.