Thread:Lightning Laxus/@comment-24411065-20180530132444

I don't think Garou is comparing his own growth with Metal Bat's ability, I think he is literally using it. Garou often picks up fighting styles of people he has fought against and there is nothing in the manga that states he is incapable of picking up fighting spirit too.

He fought Watchdog Man, and later gained his movement style.

He fought Bomb, and later gained his martial arts style.

He fought Metal Bat, and later we see him thinking back to Metal Bat and commenting on 'fighting spirit' while visibly getting stronger. It's a fair conclusion that he is in fact using 'fighting spirit' like Metal Bat is. 