That issue of sympathy would be important, I think. On the one hand, children would look at this character and want to be like him. After all, he's a superhero fighting bad guys. On the other hand, people will feel sympathetic once they learn how his transformation into a cyborg came about. And I think dealing with emotional issues like that can be helpful.
As far as emotions go, it could be good to explore how a cyborg would view the world and how introspective they are about their own emotions and motivations. Since morals and ethics have become such an ambiguously gray area in our day and age, it may be interesting to see how a cyborg might try to understand what kind of moral code they would develop. With all this power, things can become easier, right? What is the role of responsibility when it comes to my powers? What standard for my behavior do I adhere to? Maybe they would develop a black-and-white view of justice by the end, but exploring their emotional shift would be intriguing.
Granted, these are heavy topics coming from a children's show, but Japanese culture can be quite subtle in that way.
Thanks for continuing the conversation, I like discussing things like this.