The storyline is kinda complex for the series. But I think one of the main themes is for Boruto to fulfill Sasuke's plan for being a shinobi above the entire ninja world. Sasuke wanted to kill the kage. I don't think Boruto will go that far. But there may come a time when all the kage have been defeated and he has to step in and save the world again. If it were not for Sasuke forcing Boruto to learn rasengan and having the mindfulness to bring him along against Momo they may not have won that battle. I think this scenario will repeat itself again. The next time will be more extreme people may actually die. But I think it will be Sasuke's wisdom enacted through Boruto that will save them.