This is the 2658th most frequent Russian word.
чемпиона
"Чемпиона" is the genitive or accusative singular form of "чемпион," meaning "champion" in English.
'чемпионом' is used as the instrumental form of the noun 'чемпион', indicating that the subject in the state of being a 'champion' is highlighted.
Этот парень точно станет чемпионом.
This guy will definitely become a champion.
'чемпиона' here is in the genitive case, relating to the idea of 'the level of a champion'.
Мечта этого юноши — достичь уровня чемпиона.
The dream of this young man is to reach the level of a champion.
'чемпиона' in this example is in the accusative case, referring to the direct object being awarded.