Zero battle was weak, I know the author wanted to make it tense, but on her battleground, Roland had all the advantage, I know, you need to know to make it work, but Roland doesn't know how all those weapons are operated in detail, precise sizes of barrels, sizes of bullets, things like that, if those things worked, Iron Man should work too, but what is worse about that battle is the ending, I didn't even understand exactly what he did. I know he removed friction, and made a bunch of autoguns, but I was unable to visualize what happened, besides, How does one remove friction? just imagine the atoms like the and voilá? we don't even know exactly how the atom is, all those models we have are just representations, if something like that was possible, Iron man should be too. But fine, assuming that you really have to know in detail something to bring it to the battle, there was a far easier way of using very basic knowledge to defeat Zero, forget bending the laws of physics, he can change the environment right? there is one place that every kid knows how to survive, but Zero doesn't. The Space. Zero had no knowledge of the Space, nor would she survive long enough to understand what Roland space suit in reality, since she doesn't know about air pressure. I can't believe the author didn't think that