One of the most shocking moments of the One Punch Man manga to this day would probably be the time when Genos died a brutal death ... the battle against Genos were alive. After Saitama showed ...

One Punch Man's biggest battle so far has been Saitama going up against Cosmic Garou. It was a battle of epic proportions, where we saw Garou rivaling Saitama's ridiculous power level to some extent.