SSJ4 Goku: Theoretical Power
First off, I want to premise this by saying that I know GT writers never put this much thought into the SSJ4 transformation... but I did, so I wanted to hear some of your opinions.
At the beginning of GT, Pilaf summoned the Black Star Dragon, and used him to transform Goku into a child. Later on in the series, we were shown that SSJ4 is powerful enough to override a wish from the Black Star Dragon--as evident by Goku turning back into an adult whenever he assumes the form.
So if SSJ4 is powerful enough to override a wish from the most powerful Eternal Dragon in the mythos, does that mean it is powerful enough to undo other wishes(especially from weaker Dragons)? For example, could SSJ4 Goku perma-kill Garlic Jr., even though he was made immortal by Shenron?