Attack On Titan is considered by many fans to be one of the greatest manga franchises ever made. One reason behind the series' success is the unique characters that have played significant roles in the story. One of the most important characters is Grisha Yeager.
Grisha is Eren and Zeke's father, as well as a former owner of the Founding Titan and Attack Titan. Coming to Paradis from Marley, he knew many secrets that other Eldians did not for a majority of the series and kept important information in his basement, which was finally revealed in Volume 21 and towards the end of Season 3. Throughout the series, he has imparted some impactful wisdom through his speeches and writings, forever changing those he has encountered.
10 "I Am A Doctor. Take Me To A Clinic. I Can Be Of Use There."
When he gets to Paradis, Grisha pretends to not remember anything about himself other than his name and occupation. After meeting Keith, he asks him to bring him somewhere that he can use his medical skills. Keith ends up taking him to Shiganshina, where Grisha brings an end to a plague, falls in love with Carla, and begins a new life inside the walls of Paradis. For years, he pretends to not know anything of his life prior to being outside of the walls. In reality, however, he secretly hides valuable information about Marley inside his basement.
9 "There's No Holding Back An Inquisitive Mind."
Upon learning that Eren wants to be in the Survey Corps, his parents react differently. While Carla gets concerned and upset, Grisha remains calm and tells his wife that they cannot stop Eren from having such thoughts. He promises his son that he will show him what he has hidden in their basement, a promise that would never become a reality. When Eren's life changes, he becomes more curious and decides to join the Survey Corps no matter what anyone says. He eventually finds out the secrets his father kept and doesn't hold back his inquisitive mind.
8 "You're The Pride Of Humanity."
Throughout his first few years in Paradis, Grisha remained friends with Keith. After learning about the Survey Corps and what they do, Keith expects his new friend to act like most people and criticize the military branch. Instead, Grisha tells him that members of the Survey Corps are special and that Keith should take pride in what he does.
Keith appreciates what Grisha tells him so much that he feels more important than he previously had, which eventually takes control of his mindset. Despite meaning well, it may have been best if Grisha remained silent at that moment.
7 "I Should've Known Just How Sinful It Is For Parents To Indoctrinate Their Own Children."
After his sister, Faye, was murdered, their father taught Grisha about the history of the Eldians and tried to shape his beliefs. However, Grisha ended up rebelling against his parents and the government, becoming a member of the Eldian Restorationists. He fell in love with Dina and had his first son, Zeke. Believing that Zeke would be the one to save them due to Dina being a descendent of King Fritz, Grisha attempted to pass his beliefs onto Zeke, which resulted in Zeke's betrayal. Grisha realized that he became his own father and regretted what he did to his son.
6 "We Are The Chosen Children Of God!"
After joining the Eldian Restorationists, Grisha became a leader of the group and gave his followers a lot of inspiring speeches. Upon learning that Ymir was not the villain that Marley made her out to be, Grisha tells his comrades that they are right in what they plan to do and that they are Ymir's children.
His followers believed him until Zeke revealed what his parents were plotting to the government. Grisha, Dina, and their friends were taken to Paradis where they all turned into titans. Grisha was the only one that was saved. He was then given the power of the Attack Titan by Eren Kruger and started his new life.
5 "Mikasa, Come Live With Our Family."
When Grisha and Eren go to the Ackerman house, they discover that Mikasa's parents have been murdered. After Eren runs off to rescue her and the two avenge her parents, Grisha finds them and tells Mikasa that she can stay with them. This was the start of Eren and Mikasa's friendship, and if it weren't for Grisha helping her, Mikasa would not have become the soldier that fans know and love her as. One kind gesture helped a child see the light in what is arguably her darkest moment.
4 "Who Was In The Wrong? Me? Or This World? It Was Probably Both."
As his father tried to teach him about the history of their world, Grisha's views on life differed from most of the people around him. When Eren finally returned to his childhood home and went into the basement, he found a book that his father wrote.
Looking back on his life, Grisha stated that both he and those around him were wrong. He blamed himself for Faye's death and shouldn't have broken the law. But Marley was too cruel and killed innocent Eldians for things that happened years before they were born.
3 "A Child With Royal Blood... I'm Sure He'll One Day Lead Us To Victory."
When Zeke was born, Grisha holds his son and tells Dina that their son will be their savior. After he betrays the Eldian Restorationists, Zeke inherits the power of the Beast Titan and is considered by the government to be one of Marley's most trusted warriors.
After Reiner, Bertholdt, Annie, and Marcel fail to find the Founding Titan and return to Marley, Zeke goes to Paradis, where he kills many Eldians and becomes one of the Survey Corps' greatest enemies. He became the exact opposite of what Grisha intended and plans to kill every last Eldian.
2 "Humanity Has Not Perished."
Another quote from Grisha's writing, he reveals to Eren, Mikasa, Levi, and Hange that everything they had ever known was a lie. They learn about Marley and other countries, discovering that there are many more people than they previously believed. King Fritz and many of the Eldians left Marley and traveled to Paradis.
Due to the Founding Titan's ability to manipulate the minds of any Eldian, the king caused everyone in Paradis to think that they were the only humans left in the world and that the only thing beyond the walls were the titans. Learning that they were wrong, the Survey Corps find people, both friends and foes, in other countries.
1 "If You Want To Save Mikasa, Armin, And Everyone Else, You'll Have To Control This Power!"
After inheriting the Founding Titan, Grisha finds his second son and gives both the Founding and Attack Titans to Eren. He tells Eren that he will be the one to save the people of Paradis, which has become Eren's main goal. He has been willing to do whatever it took to kill the titans and claim the world as his own. Being able to see the future, former users of the Attack Titan, Grisha, and Eren Kruger, knew that Eren Yeager would gain these powers. However, only after that does Grisha realize what the cost would be by turning his son into the strongest titan in existence.