Reiner Braun was a supporting character and partial antagonist in the Attack On Titan series. As user of the Armored Titan and a resilient Marleyan warrior, there were many great expectations placed on his shoulders.
However, he has a general propensity to let down those who trust him. Whether during his time as a Scout of Paradis or otherwise, Reiner's tenacity in spite of his constant failures makes him one of the series' most compelling characters. By identifying his worst mistakes, we can better understand if he was qualified to serve the nation of Marley.
10 Reiner Did Nothing To Help In The Forest Attack
When Annie's Female Titan terrorized the Scouts in the forest, she picked Reiner out of the group. This was so that he could carve out Eren's location on her palm before using his "brute strength" to escape.
However, Reiner's actions were a disservice to both Marley and Paradis. Not only did his interaction with Annie make his true loyalties obvious, he also failed to cut down any pure titans on behalf of his Scout comrades. As a consequence, Armin immediately became suspicious of him.
9 Reiner Failed To Save Annie From Zeke
When Reiner proposed that the Warriors save Annie, Bertholdt readily agreed. However, Zeke did not, and the disagreement prompted a fight between the two Titan Shifters.
Much to the Warriors' dismay, the Beast Titan won the brawl handily. As a result, Reiner and Bertholdt were forced to forget about their captured comrade for the sake of destroying Paradis and seizing the Coordinate. Luckily for them, Annie's crystal shell provided an impregnable barrier that prevented her from being fed to the Scouts or Eren Yeager.
8 Reiner Was Responsible For Marcel's Death
During the initial foray into titan country, the Warriors did not fully understand what to expect. Reiner in particular was out of his element, which nearly cost him his life when Ymir attacked him.
Overcome with guilt about his role in making Reiner a warrior, Marcel sacrificed himself so that his friend could escape. However, his actions came at a high price; Reiner's irresponsibility lost the Jaw Titan and made the subsequent attacks against Paradis substantially more difficult. After what Marley had done, it was a miracle that Ymir agreed to return out of her own free will.
7 Reiner Blew His Cover After Utgard
After the battle for Utgard, Reiner had enough of acting like a Scout. He revealed his true identity to Eren, exposing Bertholdt in the process. Next, he transformed into the Armored Titan and abducted Eren by force.
Not only did his betrayal let down the heroes, it made the Warriors' efforts of subtlety completely meaningless. To make matters worse, Reiner would have lost against Eren at the base of the wall if the corpse of Bertholdt's Colossal Titan didn't fall on him. Since the kidnapping was so sloppy, Erwin managed to lead a successful recovery operation after he arrived at the scene.
6 Reiner Had A Meltdown After Getting Marco Killed
After sloppily revealing his identity as a spy, Reiner hunted down Marco and pinned him to a rooftop. Because of his carelessness, Annie was obligated to steal his ODM gear and make herself an accomplice to the crime.
Not only would this later get her exposed as the Female Titan, Reiner could not even keep himself together while Marco was being eaten. He raged against the pure titan he had deliberately fed the man to, drawing attention to himself and further risking the Warriors getting exposed.
5 Reiner Was Defeated By Mikasa & The Scouts At Shiganshina
When it came time for the second battle of Shiganshina, the Scouts were prepared. Hange's invention of the thunder spears allowed them to crack Reiner's armor and make an opening that they could exploit.
Although one of the heroes missed their attack, Hange joined the battle and completely dislocated Reiner's jaw. This allowed Mikasa to strike the winning blow, taking the Armored Titan out of commission and turning him into a liability for the other Warriors to look after.
4 Reiner Threatened Falco For Questioning Marley
Despairing over the expectations placed on the Warrior candidates, Falco shared his frustrations about Gabi with Reiner. Instead of relating to the young boy and conveying his own feelings, Reiner immediately threatened him with a sedition charge.
This was in spite of the fact that Falco had never displayed any profoundly anti-Marleyan sentiment so far. Reiner's kneejerk response indicated how badly the Marleyan state had brainwashed him into loyalty regardless of how much being a Warrior candidate destroyed his life.
3 Reiner Almost Gave Up Marley's Armored Titan
Haunted by the friends he was forced to abandon on Paradis, Reiner seriously considered ending his own life some time after returning to Marley. The only thing that stopped him was the sound of Falco's voice, who had no idea what was going on.
Ironically, the action Reiner was considering would have made him one of Marley's worst traitors and got his family killed. If he actually took his own life, the Armored Titan may have been reborn to an Eldian on Paradis, which would have been a massive boon to the enemies of the state.
2 Reiner Failed To Stop Eren At Liberio
When Paradis attacked Liberio, it seemed as if Marley didn't stand a chance. The War Hammer Titan was taken out of commission easily, and Pieck's squadron suffered tremendous casualties from the marksmanship of Sasha Braus.
Gabi and Falco both cried out for Reiner, who was still quietly wishing for his own death. While he met Eren on the battlefield regardless of his malaise, his armor didn't do much to protect him. Eren defeated Reiner in a single punch and would have consumed him if he hadn't already exhausted his strength fighting the other Shifters.
1 Reiner Failed To Stop Eren From Beginning The Rumbling
Marley's primary reason for attacking Paradis was to neutralize the threat of the Rumbling. As the Armored Titan, Reiner took to the front lines immediately, challenging both Eren and Zeke alongside his comrades.
However, he was almost immediately incapacitated by a shower of boulders. In the end, Pieck and Gabi were surprisingly more instrumental in stopping the Eldian plot than Reiner was, as they shot Zeke and Eren respectively. Nonetheless, ultimately no one could prevent Eren from unleashing the Founding Titan's true power and flattening most of the civilized world.