- Before the Fall manga
- Junior High manga
Cardina is a tall, slim, young man with long and curly blond hair. He has piercing blue eyes. He has some muscle tone at least to his arms, despite his outer appearance.
Cardina is a strong-willed person who is straightforward and sincere. Oftentimes, he acts upbeat towards new people. Cardina tries to the best of his efforts to hold up his reputation as the last member of the Baumeister family. He is loyal to those who offer him kindness, as shown when he came back for Kuklo, who fended off a Titan to buy Cardina time to climb up Wall Maria. To Kuklo's surprise, Cardina came running back and aided him in incapacitating the Titan.
He expresses himself to be quite playful, however retains a calm exterior when need be. That trait is shown when Xenophon takes him up as a "spare," which slightly offends Cardina, but he makes an effort to react calmly nonetheless. Cardina is also rather analytical, usually acting as Kuklo's voice of reason.
After some political turmoil involving the Baumeister family, Cardina wound up in an underground prison. While there, he notices another prisoner, Kuklo, trying to dig his way out and tells him that he will get beaten if caught. He then says there is indeed a way to escape; Kuklo says that is a lie, claiming 'you would not be here if that were true.' Cardina mentions the very fact they are here means they will be taken outside the Walls and fed to the Titans. He decides to introduce himself and tells Kuklo he was imprisoned due to political reasons, like many of the other prisoners here; this causes Kuklo to realize that Cardina was the man Sharle was betrothed to. Cardina asks Kuklo if he knows about a rumored city outside of the Walls. This city, Naraka, is believed to be the home of exiles. He goes on to talk about how the government knows more about Titans then they are letting on. When Kuklo questions why he is telling him this, he implies that he is stupid because "even after all you've been through, you keep on trying to escape. Only an idiot would fail to take the hint." Kuklo decides to help him and mentions that despite this, he still has business inside the Walls. Cardina inquires if it is about a girl; Kuklo agrees, surprising Cardina.Two weeks later, Cardina, Kuklo, and other prisoners are escorted by the Military Police in wagons to outside the Walls. When Kuklo acquires a knife from a mysterious Military Police soldier, he uses it to cut his and the other prisoners bindings. Both Cardina and Kuklo jump out of the moving wagon and run away from the impending terror of the Titans back towards the main gate of Shiganshina District. As they get closer, Cardina is spooked to acknowledge that the wagon they jumped off of had successfully reached the Titans, and they are drawing closer. Cardina and Kuklo sprint westwards from Shiganshina, but the pair are quick to notice that they are being tailed by a Titan. Though Kuklo makes it to the Wall on time, Cardina falls behind and is quickly caught by the Titan. Kuklo declares on buying them time and distracts the Titan, but is incapable of stopping it alone. Cardina joins in on the fight by clambering onto the Titan and bashing a large rock onto its teeth, rescuing Kuklo in the process. With the Titan temporarily down, the two of them run to the edge of the Wall and get reeled upwards by the same Military Police soldier who gave Kuklo the knife in the wagon. Cardina politely thanks the man for saving them. The man reveals himself to be Jorge Pikale, whom Cardina recognizes instantly. Hours later, Jorge leads Cardina and Kuklo on a wagon, and he discusses his plans. Cardina notes that Jorge used their exile to his advantage. A grateful Cardina salutes to his apparent instructor, and the two disclose their connection to Kuklo. Cardina reveals that he was pressured by his parents as a trainee to become part of the Military Police Brigade, but dropped out. Even Jorge agrees with the assessment that he had potential to be in the top ten if he had stayed.
Visit to the Industrial City arc
As they continue through the forest, they are told that Jorge is taking them to an Industrial City within Wall Rose. When Kuklo asks about Sharle, Cardina jokingly refers to how she was his betrothed and the one Kuklo kidnapped; drawing the ire from the latter. After Kuklo inquires why the Device is not being widely used by the Survey Corps, Cardina mentions that since it only goes up and down, it would be ineffective against Titans who can move in all directions. When the three of them reach civilization, Cardina shares Kuklo's thoughts about the increased presence of troops in the city. He watches the reunion between Kuklo and Sharle, and pipes up that he introduces Sharle to both him and Jorge. When she hides after learning Cardina's name, he casually mentions that the engagement between them was off due to him rebelling against his father and offers to be friends. On that note, the four of them head to a factory and are introduced to Xenophon Harkimo. Xenophon disregards Cardina and thinks of him as a "spare." Even so, Cardina tries to keep his cool and introduce himself properly. He curiously examines Cardina and Kuklo's arms, and deduces that the duo seem competent enough to be excellent fighters. With that in mind, Kuklo is interested in joining the Survey Corps, but keeps a conditional bargain with Xenophon - he must be able to use the "Device" in order to kill Titans.
Later at night, Cardina completely indulges himself in the food Sharle prepares, complimenting how good it is. He overhears one of the workers mention a previous test Xenophon conducted himself that caused a rupture and asks him about it. Eventually Cardina notices that both Sharle and Kuklo have been gone for some time, thus tempting him, Jorge, and Xenophon to go look for them. Cardina finds them on a bench, but is alarmed by Kuklo's sorrowful exclamation that the Titans will attack again and eventually break down the Wall. The next morning, Cardina notices that Jorge and Xenophon also show a lack of sleep from the night before, as they all heard Kuklo's utterance. Despite that, Jorge is determined to show them the Iron Bamboo before leaving. As they approach the main factory, Cardina remarks about how overwhelming the size of it is and asks if the Iron Bamboo is produced there as well. Soon, a carriage bearing the Military Police emblem approaches and Jentsch Dafner, the commander of the Military Police steps out, greeting Xenophon. Xenophon gives Cardina and Kuklo aliases and mentions he wished to take them to see their harvesting spot. Jentsch allows them in and salutes to them as a sign of welcome.
In the thicket of Iron Bamboo, Cardina and Kuklo learn that the Titans allegedly have a weak spot. As expected, Jorge notifies them of his findings, but Kuklo's resolve to be part of the Survey Corps has not wavered. Out of impulse, Cardina volunteers to join too. Jorge tells them the story of how he obtained his results years ago. After hearing the story (and Kuklo pledging to work with testing the device), Cardina pledges himself to the cause as well. The two teens spend the next three months repeatedly testing and making notes of the device as it gets modified by Xenophon and the other workers. Soon, Jorge returns and takes them back to Shiganshina in order to do a proper testing of the device against the Titans. Noting that he is not as confident as Kuklo, Cardina asks Carlo and Jorge to slowly lower him down. However, he is spotted by the Titan Ogre and it charges him.
- Kuklo Munsell - Initially, Cardina thought of Kuklo to be headstrong, and stubborn beyond the point of reason. However, his opinion has long changed of Kuklo ever since their first encounter. This is due to the fact that Kuklo saved Cardina a number of times, proving Cardina wrong.
- Jorge Pikale - Cardina thinks highly of Jorge, as he was Cardina's instructor while he was still a trainee. The two of them share a mutual trust and respect for each other. For example, Jorge expressed that Cardina had the potential to rank in the top ten.
- Sharle Inocencio - Though Sharle acts fairly hostile towards Cardina regarding that he was meant to be her betrothed, Cardina works on being as friendly as possible with Sharle, attempting to show no ill-will after all that happened between them.
- Xavi Inocencio - It is currently unknown what type of relationship the two share, but they appeared to get along as both trainees and as individuals. Cardina states that Xavi used to brag about cutting out the Titan's son's right eye.