According to aspects of the present disclosure, systems and methods for controlling the direction of a drilling assembly within a borehole are described herein. An example system may include a housing 201 b (FIG. 2B) and a variable flow fluid pathway 203 (FIG. 2B) within the housing 201b. A fluid-controlled drive mechanism 209 (FIG. 2C) may be in fluid communication with the variable flow fluid pathway 203. Additionally, an offset mandrel 212 may be coupled to an output of the fluid-controlled drive mechanism 209. The offset mandrel 212 may be independently rotatable with respect to the housing 201b. The system may also include a bit shaft 216 pivotably coupled to the housing 201b and coupled to an eccentric receptacle of the offset mandrel 212.