Vincent Starci is the main protagonist of the series. At the age of ten, he received the Ancient Blade of the Elements, the prized treasure of his family, and with its energies is able to control elemental beings.
Vincent's appearance has changed noticeably over the series. In the first game, he is of average depiction with blonde hair and black eyes, and wears a plain red shirt, black jeans and blue trainers. Super Blade Boy added intricate white patterns to his shirt, whereas Box of Secrets changed his eyes to a green colour and made his hair spikier. Finally, Text Code Backwards completely redesigned him. From here onwards, his shirt is light blue (but retains the white patterns), and he wears an open red jacket along with it. He also wears a silver pendant emblazoned with a multi-coloured gemstone and connected to two large pieces of metal on his shoulders which connect to strands of metal that spiral along his arms. In all 3D instalments of the franchise, he has a second character model depicting him in a blue and orange swimsuit, although this model is only used for beta testing.
Vincent was initially depicted as a stereotypical silent protagonist in the early games. In Box of Secrets, he was given dialogue, being depicted as a kind-hearted individual who cannot ignore those in need of help.
Sophia Starci is Vincent's wizard-like sister. Introduced in Super Blade Boy (albeit referred to as Sophie in this game), she served as a minor supportive character, although in The 64 Threats she was given a more significant role, in which she helps Vincent pinpoint the locations of the 64 Threats.
Sophia was initially depicted much like Vincent, being ten years old with an average appearance. She had long brown hair and black eyes, and wore a blue wizard's robe with plain brown boots. Box of Secrets gave her orange eyes and shorter hair, although in Text Code Backwards her robe was much more detailed, her hair was lengthened and she wore a wizard's hat that matched her robe. This design was kept consistent for the rest of the franchise.
Sophia is quite shy, often fearing her incredible magic powers. As the series went on, however, her more carefree side began to show more and more.
Christopher Sistas is Vincent's best friend. Making his debut in the third game as an implied character in the manual, his first legitimate appearance was in Box of Lies as a character who gives tips to the player. In Four Elements and all future games, he was a playable character in the Minigames and could help the player by giving information on their Elements.
Christopher is roughly eleven years old, with white hair and black (later purple) eyes. In The Art of Blade Boy and Box of Lies, he wore the same attire as Vincent, albeit with a yellow shirt that possessed blue patterns, green trainers and a red belt with intricate black designs. Four Elements redesigned his attire, giving him a plain blue shirt, yellow jeans, dark green trainers and a plain red belt. He also has pale blue markings all across his body (although these markings can only been seen in full by hacking the game), which he supposedly received in a paint-based accident. Like Vincent, he has a second model for beta-testing, showing him in a grey and red swimsuit.
Christopher is fairly relaxed, not worrying when even the direst of troubles show up. He is also shown to be very knowledgeable about the world around him.