|◄ Preceded by|| Uri Reiss|
|Followed by ►|
| Rod and Uri's father|
| Frieda Reiss|
|◄ Preceded by|| Uri Reiss|
|Followed by ►|
| Rod and Uri's father|
| Frieda Reiss|
|In the not too distant future, this world will crumble. And in humanity's fading twilight...I wish to build paradise.|
|— Uri Reiss to Kenny Ackermann|
Uri Reiss (ウーリ・レイス Ūri Reisu?) was the younger brother of Rod Reiss and the paternal uncle of Frieda Reiss and Historia Reiss. He was the true king of the Walls for some time until the year 842 and was Kenny Ackermann's best friend. He inherited the Founding Titan from his father, and passed it along with the crown to his niece, Frieda Reiss.
He was a frail man who usually wore a simple light colored robe. He had neck length, light gray hair. He also had light, weary eyes; with a calm, wise beyond his years type of expression. After inheriting the Founding Titan, Uri's eyes would change between their normal light color to a purple look, which meant he was bound by the will of the First Reiss King. Like most of the Reiss family, he was also rather short.
Despite his upbringing and his responsibilities, he disagreed with his father's policy to keep humanity in bondage to the Titans, believing that their family should use their power to eliminate the Titans and return the world to mankind. He was brave enough, and held his ideals strongly enough, to volunteer to be the one to inherit the Founding Titan from his father, despite the risk of becoming possessed by his ancestor's ideology.
He refused to hold a grudge against Kenny, despite the latter's rudeness and repeated attempts to attack him; believing that because of the Reiss family, the Ackermann's hate was justified. He even went so far as to bow down to Kenny and formally apologize.
He was also a very calm man. He did not show any signal of pain when Kenny hurt him with a knife and he did not hesitate when Kenny aimed him with a pistol.
Even though he could not rid the world of Titans as he originally wanted, he truly cared about everyone. He wanted to make a paradise for the remaining members of humanity, believing not far in the future that their world would fall.
Uri was the second born of Mr. Reiss and younger brother of Rod Reiss. As their father was the inheritor of the Founding Titan, the "invincible power" that could stop the terror of the Titans once and for all, Uri and Rod pleaded with him to free humanity from their encagement, but he always refused to do so or to explain why he would not.
Sometime later, Uri volunteered to be the next Founding Titan with the full intention to use it to stop the Titans, and according to Rod, he requested him to pray; as the amount of power the Founding Titan would give him would effectively make him a god.
However, after Uri inherited the power of the Titans and memories of the world from their father by eating him in the succession ritual of the Reiss family, Rod could tell by his eyes that he had inherited that same ideology; and as Mr. Reiss and all the other kings before them, Uri refused to either stop the Titans and to tell everyone the lost memories of mankind.
After Uri inherited the Founding Titan, Kenny Ackermann discovered that Uri was the true king, and tracked him down and tried to kill him. However, he was stopped by Uri, who caught him on his Titan form. Kenny did not give up after this, even throwing his knife at Uri and pointing his gun at him. However, even after this and the fact that Rod insisted that Kenny had to die, Uri spared his life. He said that as an Ackermann, he deserved to point his knife at him, due to the persecution that the monarchy had plotted against them.
After this, Uri, with the knife still stuck in his arm, bowed before Kenny and apologized because of the persecution of his family and his frustrated attempt to create a paradise within the Walls. This heavily surprised Kenny, who wondered how a powerful King like him could bow before someone like himself.
From that point on, Kenny became not only his bodyguard, but also a close friend, and Uri ceased the attack on the Ackermann bloodline. The two spent much time together talking, with Uri even telling him that his power will soon be inherited by Frieda Reiss.
Sometime after this, Uri was chained hand and foot underneath the Reiss Chapel as his successor, Frieda, sobbed and injected herself with the Titan syringe. His brother, sister-in-law and nephews witnessed his death. He smiled as his 15-year-old niece Frieda transformed into a Pure Titan and ate his upper body, inheriting his position, the power of the Titans, memories of the world, and will of the First King.
Many years later, as Rod is trying to convince Historia to eat Eren and become the next Founding Titan, he tells her about Uri, their unsuccessful attempts to convince their father to stop the Titans, and how Uri had requested him to pray before receiving the Founding Titan. Rod prays to Historia in the same fashion, but she does not believe his story and throws him to the floor, calling him a liar.
While dying, Kenny ponders about his mutual past with Uri, as well as their friendship. Kenny thinks that he wanted to see things like Uri saw them, from a vantage point. He then tells Levi that every person that he had met in his life was a slave for something, even Uri, a slave to his dreams.
Uri appeared to be quite an intelligent man, surmising from his encounter with Kenny that he was of the Ackermann bloodline. Though he is never shown fighting, he was able to block a knife that was aimed at his throat with his arm.
Though his full Titan form is never shown, he possessed the same regular abilities as Titans and others with the power of the Titans.
- Founding Titan: Because of his royal blood, Uri had the full abilities of the Founding Titan and could manipulate the memories of Subjects of Ymir. Rod calls this the "invincible power."
- Regeneration: Like all Titans, he possessed healing abilities. He was able to heal from a knife launched by Kenny that pierced his left arm.
- Partial Transformation: Similar to Ymir, he was seen holding Kenny in his Titan form's fist while almost completely outside of his Titan body, with only his right hand merged. While doing this he could talk and move both of his bodies without any problem.
- Kenny Ackermann - After witnessing the humility Uri showed a lowlife like him, Kenny developed a deep respect and admiration for Uri. The two became friends and used to spend time talking, with Kenny being impressed by Uri's empathy and compassion, going as far as wishing to inherit Uri's Founding Titan in hopes to become such a compassionate person himself. Kenny saw Uri as the most powerful being, believing that only a being with such immeasurable power could allow itself to feel such compassion for others like Uri did. Even after his death, Kenny remembered Uri fondly, as he threatened to kill Rod after the latter called Uri a whimsical person.
- Rod Reiss: Before Uri inherited the Founding Titan, Uri shared the opinion with Rod that the Titans should be stopped. They tried to convince their father to change his opinion and eliminate the Titans, but it was futile. When Uri inherited the Founding Titan, he asked Rod to pray for him.
- Rod and Uri's father: His father was the previous Founding Titan. Along with Rod, the two brothers would constantly beg him to release humanity from their encagement, but he always refused, never stating the reason why. While Rod was once locked behind bars for this, this never appeared to have occurred with Uri. When it came time for the power and position to be passed to a son, Uri volunteered, asking Rod to pray.
- Frieda Reiss: Though not much interaction was seen between the two, it can be assumed that Uri cared about Frieda, which is shown when he smiled as he was about to be eaten by his niece. During the succession ceremony, Frieda shook and cried, as she did not want to eat him.
- Rod and Uri's father (as a Pure Titan)
- Uri's name is Hebrew in origin meaning "my light," "my flame," or "illumination."
- During Uri's conversation with Kenny Ackermann by a lake, ducks can be seen in the background. Then when Uri says "Kenny...In the not too distant future, this world will crumble", the scene focuses in on the ducks. In Japanese, "duck" (カモ Kamo?) or "good duck" (いいカモ Ī kamo?) can mean "easy target" (similar to the English idiom "sitting duck"). This is appropriate because the First Reiss King erased the memories of the Eldians inside the Walls and made a vow renouncing war which prevents them from using the Founding Titan to defend themselves. He knew that the rest of the world will attack them eventually, and that his temporary paradise inside the Walls will some day end, but he accepted it if it ever happens. He made them all "sitting ducks", blissfully unaware and helpless of their incoming destruction.