This study focuses on how a slanted magnetic field and rotation affect viscoelastic fluid it moves peristaltically via porous media in a tapered asymmetric slanted channel with a variable viscosity and the mixed convection heat transfer is investigated. Under the presumption of a long wavelength and a short Reynold number, the equations of continuity, momentum, and energy have been developed. The flow is examined while moving at the wave’s velocity in a wave frame of reference. The series of analytical solutions for the temperature, velocity, and stream function can be obtained using the perturbation technique. Using the Mathematica package, the effect of several fascinating parameters on temperature, axial velocity, and stream function in a flow system has been produced and described through graphical representation.