Appearance/discussion of Academy units.

They are specifically coated with a stainless composition. Who would want a golem to be unable to raise its arms during battle due to rust? So, the mages, that is, the gremlins, polish them with a certain blue substance. As for the unupgraded ones, they are simply not polished; take a closer look... not much changes in their appearance, only the rusty ones are simply unreliable.