One Punch Man (Manga) Vol 29

S-class hero Blast suddenly appears before Saitama and Flash in search of a mysterious box! But what is it about the box that has the Hero Association's top hero chasing after it? Meanwhile, several heroes are locked in a fierce battle with Monster Association executives when Genos's power core becomes unstable! Viz Media Llc
(W) One (A) Yusuke Murata