Leon Garcia, also known by his codename Dandelion, is a former professional soldier who served the Vatican Papal State before becoming a prisoner of the church. His background is marked by a violent past: he was a decorated soldier noted for his bravado, but he was convicted of murdering his wife and thirty clergymen, a crime that earned him a sentence of a thousand years in prison. Because soldiers within the Vatican system are also considered priests, this act was treated as an exceptionally serious offense, and he was held under the threat of execution. While imprisoned, he is occasionally permitted to assist the AX agency, the Vatican’s special operations group, with their missions, and each successful assignment reduces his sentence by a set number of years. He first appears when he is partnered with Abel Nightroad to investigate vampire attacks on ships near the island of Never Land.

Personality-wise, Leon projects a gruff, abrasive exterior and is quick to take offense if anyone calls him an old man. He fights with both sharp throwing disks and a heavy bazooka, and his combat style reflects his military training. Despite his rough demeanor, he harbors a deep compassion for others, especially children, whether human or vampire, and still shows signs of caring for those around him. His motivations are rooted in his desire to atone for his past crimes and to possibly reunite with his daughter, whose whereabouts are unknown. He carries a pendant with a picture of his daughter around his neck at all times, a constant reminder of his loss and his hope.

In the story, Leon serves as a supporting character within the AX team. His role is that of a skilled but reluctant operative, a prisoner who earns his freedom one mission at a time. He often clashes with others due to his bluntness but ultimately proves to be a reliable ally. His key relationships include working closely with Abel Nightroad and other members of AX, particularly during field operations. Though he is not a central figure in the overarching political conflicts, his presence provides a grounded, human perspective within the supernatural and political turmoil of the setting. Over the course of the series, Leon undergoes limited but meaningful development: he gradually earns reductions in his sentence and begins to move away from his past life as a hardened killer, showing more of his protective, fatherly nature. His notable abilities include exceptional marksmanship, proficiency with unconventional thrown weapons, and a pragmatic, soldierly approach to combat that makes him effective against both human and vampire foes.