A cube made from the massive pile of commons (and some uncommons) I had lying around, the Residuals of all the packs I have opened.
My first cube was constructed with a particular theme in mind that drove all of its design. This cube is not focused on a theme, but rather on more common archetypes. With no cards required by theme, Residual is can change and evolve much more than my main cube; a place to hone my cube building skills.