Lector is an Exceed and a member of the Sabertooth guild in Fiore. As an Exceed, he is a small, bipedal cat with dark brown fur covering most of his body, while his face, belly, paws, and the tip of his long tail are pink. He has large pointed ears and prominent tufts of dark fur near his cheekbones where his whiskers are located. He wears a blue, sleeveless button-up vest that is left open with three dark round buttons on the right side.

Lector is introduced as a highly arrogant cat who habitually belittles others, considering everyone inferior to Sting Eucliffe and, by extension, the Sabertooth guild as a whole. During the Grand Magic Games, he constantly boasts that Sabertooth members will easily win their matches and even scolds Frosch, the Exceed partner of Rogue Cheney, for simply asking who will win. When events do not go as he expects, such as Yukino Agria's swift defeat or Sting quitting a race, Lector is left stunned and speechless. His arrogance is severely shaken after witnessing Sting and Rogue being defeated by Natsu Dragneel; this loss humbles him, and he later tells Jiemma that Sting learned more from defeat than victory. Lector’s deep devotion to Sting is the core of his personality. After seeing Sting fight for the first time, Lector followed him and begged to become his student, claiming he wanted to become strong. Sting accepted, and the two formed an inseparable bond. Years before the main story, Lector bragged to others about Sting having killed a dragon, which led to mockery and upset him greatly; Sting comforted him and promised to defeat the man known as Salamander, Natsu. Lector’s motivations revolve entirely around supporting Sting and seeing him succeed, and he exhibits a fierce loyalty that sometimes manifests as boastfulness but also as genuine fear and tears when Sting is in trouble.

In the story, Lector plays the role of Sting’s constant companion and ardent supporter. He and Frosch travel to Magnolia to gather information about Natsu before the Grand Magic Games, and he is present for most of the tournament, cheering for Sabertooth and reacting emotionally to each match. After Sting’s defeat by Natsu, Lector tries to defend Sting and Rogue when Jiemma berates them, revealing his own Sabertooth guild mark. Jiemma attacks him, but Minerva uses her magic to whisk Lector away to another dimension, saving his life. Lector is then used as ransom to force Sting to win the Games, only being freed after Sting surrenders. The two share a tearful reunion. Later, Lector encourages Sting when word of the coming dragon attack spreads. His development is marked by a shift from pure arrogance to a more humble and emotionally open character after experiencing the reality of defeat alongside his partner.

Lector’s key relationships are primarily with Sting, whom he idolizes, and with Frosch, whom he often scolds but treats as a fellow Exceed. He also has a tense dynamic with Jiemma, who dismisses him as a mere cat. As an Exceed, Lector possesses the natural ability called Aera, which allows him to sprout large angelic wings from magic circles on his back to fly. He is also capable of human speech. Despite being a member of Sabertooth, his combat role is minimal, and his primary functions are companionship, scouting, and morale support for Sting.