Active colloidal microcrystallites are introduced capable of generating flow patterns around or through their porous network. The generated flow drags nearby free Janus microspheres toward the microcrystallite and create self-assembled active clusters with multiple moving parts. The translational movement of free Janus particles transitions to continuous spinning. Weight-anisotropy of a Janus particle leads to a time-varying angular frequency and the gravitropic spontaneous realignment of the rotational axis to a preferential direction. The dynamics of the self-assembled active structure remains stable over long time periods, despite being subjected to significant noise, for example, Brownian forces.