This study has been carried out to understand the unsteady MHD slip flow of a water-based ternary hybrid nanofluid including spherical Cu, titanium dioxide TiO2 and cylindrical Al2O3 nanoparticles across an angled sheet. The complicated scenario above investigates how ternary-hybrid nanofluid behaves when it is stretched across an inclined surface in the existence of a magnetic field. In complex thermal systems such as energy-generating technologies and cooling mechanisms, an understanding of this relationship is essential. In the existence of first-order velocity slip, the heat transfer has been examined taking into account the non-Darcy Porous media, activation energy, and heat source. The study is more accommodating because of the Soret effect. The relevant similarity transformations are applied in primary equations and a built-in bvp4c program is employed for solutions. The effectiveness of the numerical approach is demonstrated by a thorough agreement with results that have been published in the past. The key conclusions are as follows: greater values of the first order slip parameter cause the flow to slow down; an increase in Soret number causes the flow to speed up; and in both scenarios—that is, with and without velocity slip, fluid movement drops caused by higher values of the chemical reaction. The Forchheimer parameter lowers fluid velocity while activation energy enhances the fluid concentration.