Like Yang's other students, "Chuck" was presumably either a pupil of Yang at the Temple of Airjitzu before it became cursed, or entered it later seeking to learn Airjitzu. As a result, he was either turned into a ghost along with Yang's other original students or subsequently became one after failing to escape the temple before sunrise; being enslaved by Yang's dark magic.
Yang later ordered "Chuck" to stand guard over Cole while he set out to open the Rift of Return; Cole named Chuck during this time and attempted to convince him to help him defeat Yang. The enslaved Chuck proved deaf to Cole's pleas, forcing Cole to defeat him and set out to stop Yang alone. Chuck later joined the others in battling Cole at Yang's command, but proved no match for him and were later freed after Cole overcame Yang. Chuck and the others then used the Rift of Return to return to human form.