Given how action-packed most anime tend to be, violence is almost always the only way to resolve conflicts and problems. These anime characters know that this is the reality, but that doesn't mean they agree with it.
Whether it was because of their morals or for fear of the harm they may inflict, these characters became pacifists in the face of death and destruction. Arguably, their choice to uphold peace made them the strongest people on the battlefield.
10 Neon Genesis Evangelion — Maya Ibuki Was Too Innocent For Evangelion's Darkness
Whether they were piloting an Evangelion or not, almost everyone living in Tokyo-3 was emotionally troubled. Maya was the rare exception since, outside her crush on Dr. Ritsuko Akagi, she didn't have any debilitating angst. This, however, was not a good thing, since it meant she wasn't going to survive a world as bleak as Evangelion's.
Maya was just too nice for Neon Genesis Evangelion's world, she was almost always the first to crack under the pressure of an Angel attack, and she couldn't even pick up a gun to defend herself during the JSSDF's invasion of NERV. It isn't too surprising that she looked more relieved than anything when Instrumentality came for her.
9 Baccano! — Jacuzzi Splot Is Too Nice To Start A Fight
It goes without saying that Jacuzzi was the most cowardly and spineless character in Baccano! That being said, Jacuzzi's high anxiety, excessive apologizing and crying, and lack of physical strength aren't bad things. Instead, they're actually his most famous assets and the very reasons why his gang is fiercely loyal to and protective of him.
Jacuzzi isn't incapable of summoning his bravery to stand up for himself or others (especially his girlfriend, Nice Holystone), but he needs a lot of pushing to get to that point. If he could choose, Jacuzzi would rather not fight, especially when the mere threat of violence was more than enough to reduce him to a blubbering, crying mess.
8 Bleach — Orihime Inoue Only Used Her Powers For Defense & Healing
Almost everyone in Bleach is ready or itching for a fight, with Orihime being the rare exception. Like her friends, Orihime has supernatural powers, but she exclusively uses them to summon barriers or heal injuries. In brief, Orihime is so kindhearted that she would rather heal her enemies instead of even thinking about wounding them.
Not helping matters is the fact that Orihime's powers are empowered by her desires. To wit, her defensive and healing capabilities are immensely powerful, but her offense is practically non-existent. Orihime isn't incapable of inflicting some damage, but the fighting is better left to Ichigo or her longtime friend and defender, Tatsuki.
7 Durarara!! — Simon Put His History Of Violence Behind Him
Little is known about Semyon Berzhnev's past, save for the fact that he worked for the KGB and Russian organized crime before migrating to Japan. What's clear, though, is that Semyon wanted to get away from this dark past and started a new, peaceful life in Ikebukuro as Simon, the friendly chef and co-owner of the restaurant Russian Sushi.
Simon is such a pacifist that he resents even the mere mention of violence, and this stems from his guilt for his bloody past. The few times Simon broke his oath were in self-defense, or to teach Izaya Orihara a lesson.
6 Re:Creators — Mamika Kirameki Realized How Dangerous Her Powers Really Were
In her kid-friendly anime, "Magical Slayer Mamika," Mamika was a typical magical girl who easily defeated evil with the power of love and colorful spells. In Re:Creators' reverse-isekai world, however, Mamika was a dangerous spellcaster whose cutesy powers leveled entire city blocks. Upon realizing this, Mamika swore to never use her powers again.
For the remainder of her time in Re:Creators, Mamika avoided using magic and tried her best to end the fighting through compassion and diplomacy. It was only when her efforts at peacekeeping failed and during her last moments that she used Magical Splash Flare against Altair in a last-ditch attempt to stop her.
5 Mob Psycho 100 — Shigeo Kageyama Doesn't Want To Lose His Temper Again
Mob always had immense psychic powers, but he chose to keep them at bay. Years ago, Mob lost control of his powers and attacked the high schoolers who were bullying him and his brother, Ritsu. Unfortunately, Ritsu was caught in the chaos. From then on, Mob swore to never use his powers unless his mentor, Reigen, gave him permission to.
Mob only used his powers to either exorcise ghosts that he and Reigen were paid to get rid of, or as a last resort if diplomacy failed. On most days, Mob kept his emotions in check to avert the risk of losing control again, or he ignored his powers since Reigen wisely (if unintentionally) taught Mob that being psychic didn't make him superior to others.
4 Black Lagoon — Rock Thinks Committing Violence Is Beneath Him
Rock really stands out in Roanapur's seedy underbelly, mainly because of his refusal to even hold a gun. Though this was initially because he was too scared to even think straight, Rock gradually became so cynical and jaded that even the idea of killing or hurting someone himself seemed below him.
Rock's best weapon was his cunning business mind, which he used to manipulate Roanapur's residents into doing his bidding without them even realizing it. As far as Rock was concerned, what he did was the lesser evil. That, and making others do the dirty work was more effective and gratifying than getting his hands bloody.
3 Psycho-Pass — Akane Tsunemori Always Upheld People's Right To Live
When Akane joined the Public Safety Bureau, she swore to protect the innocent and bring the guilty to justice. But unlike her jaded colleagues and especially the Enforcers, Akane chose to do so non-lethally. Even when she had the legal and personal justifications to do so, Akane chose to protect the sanctity of life no matter what.
Whenever she could, Akane negotiated with the suspect or used a taser to bring them in safely. Akane's actions greatly amused and irritated the Sibyl System, which wanted to turn her into a useful pawn but always failed to do so. By Psycho-Pass' third season, it's said that Akane killed someone but, given Sibyl's untrustworthiness, it's hard to believe this dubious claim.
2 Mobile Suit Gundam SEED — The Orb Union Chose Self-Destruction Over War
As the war between the Earth Alliance and PLANT dragged on, the few remaining neutral nations were forced to pick a side or risk retaliation. One nation that both Naturals and Coordinators wanted on their side was the technologically-advanced and self-sustaining Orb, which was famous for its space catapult and unwavering neutrality.
When the Alliance demanded that Orb lend their catapult and join Earth's war effort, Orb and their leader Uzumi Athha chose death. Uzumi knew that siding with either the Alliance or PLANT would endanger Orb's people and benefit an aggressor, so he and his countrymen chose to destroy their prized space catapult and beloved homeland instead.
1 Attack On Titan — King Karl Fritz Erased The Eldians' Instinct For War
A millennia ago, the Eldians were a powerful empire whose conquest was made possible through Titans' power. However, not everyone was proud of this history. King Karl Fritz, the 145th Eldian king, resented his ancestors' bloody legacy, and devised the empire's fall as atonement. What's more, he erased his descendants' capacity for violence.
With the Founding Titan's powers, King Fritz rewrote Eldians' memories and renounced war in his peoples' stead. As such, all Eldians could not use the Titans' power as a weapon, and they would accept their total annihilation as payment for their forefathers' sins. Before Eren Yeager broke it, King Fritz's vow held fast for countless generations.