The Chrono Stone is a special stone with a "C" in the middle of it.
The Chrono Stones are gems with an iconic 'C' on it. Chrono Stones are made when a human with strong willpower is getting sealed, which alters time and creates a Chrono Stone with the person's soul.
It first appeared in Episode 11. Beta used the Sphere Device to seal Endou Daisuke, but his willpower protected him and a collaboration in the timeline caused him to turn into a stone: the Chrono Stone. Imprisoned in this stone, Daisuke can still talk. He told Raimon about the Hasha no Seiten and the Ultimate Eleven.
In Episode 24, it is shown that Zanak was holding the Chrono Stone that holds Endou Mamoru, which probably means he got it or stole it from El Dorado.
- The reason why the anime is called "Inazuma Eleven GO Chrono Stone" is because of these stones.
- Each of these stones have a different shape and color. For example, Daisuke's stone is orange and has a hexagonal shape, while Endou's is purple and has a triangular shape.