I've got to say, I really hope there's a good reason why Metal Bat is several hundred times more powerful here than he was against Hero Hunter Garou. He's taken far fewer hits over a relatively short time period, whereas back then we had more fights and more build up to Metal Bat being able to fracture buildings and whatnot.
If he just gets the power-up because of "fighting spirit" and there's no further elaboration, Metal Bat went from being weaker than guys like Gums and base Fuhrer (at max fighting spirit), to someone who can parry dozens of titanic fists, fists which can fracture cities and then rock them like a cowboy on a rodeo bull because... well, 10,000 BS clones (a tiny fraction) punched him and SC ran into him