  We present, experimentally and theoretically, a scheme for dressed-state
electromagnetically induced transparency (EIT) in a three-step cascade system
where a four-level system is mapped into an effective three-level system.
Theoretical analysis reveals that the scheme provides coherent state control
via adiabatic following and provides a generalized protocol for light storage
in uniform phase spin-waves that are insensitive to motional dephasing. The
three-step driving enables a number of other features including spatial
selectivity of the excitation region within the atomic medium, and kick-free
and Doppler-free excitation that produces narrow resonances in thermal vapor.
As a proof of concept we present an experimental demonstration of the
generalized EIT scheme using the $6S_{1/2} \rightarrow 6P_{3/2} \rightarrow
7S_{1/2} \rightarrow 8P_{1/2}$ excitation path in thermal cesium vapor. This
technique could be applied to cold and thermal ensembles to enable longer
storage times for Rydberg polaritons.
