Furlan was a young man with light gray eyes and ash blond hair. His hair was short with shaggy layers and bangs which hung over his forehead, between his eyes. Before he joined the Survey Corps, Furlan's civilian clothes featured a simple long-sleeve white shirt with a light blue vest and knee-high boots. After his enrollment, Furlan wore the typical uniform of the corps with a light shirt underneath.
Furlan, in contrast to Isabel, was very focused and able to make the distinction between when to have fun and when to be serious. Like Levi, Furlan was usually depicted as level-headed and calm, but he disliked when things got out of control. He had a clear understanding of when he was defeated, and stopped resisting if he knew that he had lost; this was shown during his capture by the Survey Corps. Furlan placed a great deal of trust in Levi and followed his decisions and leadership without question.
Prior to the fall of Wall Maria, Furlan was a delinquent roaming the capital's Underground District. At one point, Furlan decided to test Levi's strength by having him fight a group of thugs. Furlan's plan was to see if Levi was worth recruiting into his group of thugs or not, and he was surprised to see Levi beat them all single-handedly. He decided to join Levi, though how he convinced Levi to let him join him is unknown, as he neglects to tell Isabel the rest of his story.
Furlan, Levi, and Isabel were notorious for having a strong reputation due to Levi's strength. After the three obtained and became skilled using vertical maneuvering equipment, they would use it around the Underground City, as it made their illegal business easier to accomplish and gave them hopes of rising above their lives in the city. Furlan eventually found himself and his companions captured by Erwin Smith of the Survey Corps. When Levi was blackmailed into joining the Corps, Furlan and Isabel chose to follow him, and all three resolved to one day claw their way into a better life on the surface.
On his first expedition outside the Walls, Furlan assisted Levi in taking down an Abnormal Titan. While obviously nervous and unsettled at the thought of fighting a Titan, he gained his courage and morale upon seeing Levi charge into battle. On cue, he and Isabel sliced the Titan's knees in unison, allowing Levi to finish the Titan off.
The next day of the expedition, during heavy rain, Levi decided to take the chance to hunt down Erwin and complete their original mission, using the rain to his advantage. Furlan advised caution, but Levi brushed him off. Despite Furlan's protests, Levi forced the conversation to a close and set off to kill Erwin.
Soon after making it back to the squad, Furlan and Isabel's squad was attacked by five Titans. Levi returned to find the Titans attacking the squad with Isabel and Furlan trying to avoid the battle. As they tried to flee, Furlan's horse, startled by a Titan, fell atop Furlan's leg, pinning him to the ground. As he tried to free himself, Isabel used her vertical equipment to distract the Titans, barely managing to avoid their grips. When she moved in to kill one, she ended up slipping and hanging by her equipment across the Titan's back. As another Titan got a clear view of her, it launched itself straight at her, crushing her between them. Furlan had managed to free himself, but Isabel's death caused him to turn and confront the Titans, realizing too late that his fall had badly damaged his equipment. Thinking that it would be the end for him, squad leader Flagon Turret distracted the Titan while giving Furlan orders to retreat. Furlan frantically watched as Flagon was eaten by the Titan. Still trying to fight, he was the next one to be grabbed. As he is lifted in the Titan's hand, he caught sight of Levi. He waved to him in a farewell gesture like he used to in the streets of the underground. Furlan was eaten just as Levi came within grappling range. Filled with rage, Levi sliced the Titan's stomach open and pulled what is left of Furlan out. By that time, however, Furlan was already dead.
Having witnessed the deaths of the first two true friends he ever had, Levi went into a blind rage and killed all the Titans. When Erwin, who had seen the steam from the fallen Titans, arrived on the scene, Levi attacked and attempted to kill him, blaming him for their deaths. Erwin questioned what would have happened if Levi had stayed with his friends instead of leaving them to fend for themselves while he had gone forward. This caused Levi to believe that it was his own arrogance that got his friends killed. Erwin refuted this, stating that the real reason for their deaths were the Titans and the lack of knowledge that the humans had on them. He went on about how the rich humans inside the Walls choose to turn a blind eye to the swath of destruction that is happening right outside their doors. To conclude, Erwin stated that the Scouts are Humanity's only hope of being free and asked Levi again to join them. This time Levi accepted willingly.
The surviving Corps members made a full withdrawal for the Walls while Levi took one last look at the steaming corpses of Titans that would serve as a grave for Furlan and Isabel.
Furlan stole vertical maneuvering equipment and, along with Levi and Isabel, trained himself to the point of proficiency and used it on their underground missions. He almost escaped from a Survey Corps squad, mankind's greatest soldiers, and he stated that he, Levi, and Isabel had escaped from the Military Police several times before.
He seemed to be smart and skillful, as seen when he confessed that he trained himself with the vertical maneuvering equipment and in his ability to keep a cool head.
- Levi - Having heard rumors of Levi's strength, Furlan originally set up a test to see how strong he was. He was amazed at Levi's skill and hoped he could convince him to join his gang. After Levi refused, he joined up with Levi instead. The two became close friends, with Levi greatly valuing Furlan's opinions and strategies.
- Isabel Magnolia - Though they were usually at constant odds with each other, they were close friends and showed a great level of cooperation and synchronization. With few words between them, they operate with extreme precision.