School of "heroes"

In a world where it was common to see great heroes fight against various things that will surpass the government of any country If objective was clear, and it was only one ... protect the entire society from any threat that will arise on the planet The objective was clear, and the heroes had never failed, but for everything there is a first time The heroes failed only once, and on that occasion the world experienced an apocalypse ... the heroes returned but the battle was intense and ended up costing the lives of some heroes Finally, with your children, you will be able to make a better organized and stronger team again to prevent that from happening again. After all, what could go wrong?