Cane just wanted to stay busy. Helping find missing children seemed like a worthy cause, even though his agreement forbade him from doling out his brand of justice to the ones responsible.
When he stumbles upon a sadistic family responsible for the suffering of a growing number of children, he finds it increasingly difficult to restrain himself. His agreement would have him simply notify the police, but these people deserve condemnation.
Or better yet, Canedemnation.