Why are you acting surprised? This has always been in him and has been alluded to many times before in the show, in particular when he saved his brother when they were kids or some such.
To me this episode was awesome, all-time favorite to me. I'm still hurting from Dimple's last episodes, and I don't know how Mob can move on from this event after all is said and done. Feels like we're reaching the end of the rope with this series. I don't know how far along the manga we're though, but I just don't see where Mob will fit after all this destruction... unless we get some restorative BS maybe?