This research aims to understand the comparisons of entropy optimization of MHD Casson and Ellis penta-hybrid nanofluid flow over a three-dimensional rotating exponentially stretching sheet with thermal radiation. The study is further enriched by considering nanoparticles which are \(Ag/Au/MgO/Cu/TiO_{2}\) suspended in two different base fluids: Ethylene glycol (EG) and water. The corresponding non-dimensional equations are numerically resolved using the bvp4c method. We use similarities in the transformation of nonlinear coupled partial differential equations into nonlinear coupled ordinary differential equations. Several important dimensionless physical parameters such as temperature, velocity, entropy, Bejan number, skin friction, Nusselt number, and streamline has been utilized for analysis, with the corresponding results for skin friction and heat transfer. With an increase in the magnetic field, the fluid velocity decreases because the Lorentz force acts as a resistive drag on the fluid motion, opposing its flow. Nanofluid compositions have progressively advanced from simple nanofluids to hybrids, tri-hybrids, tetra-hybrids, and now penta-hybrids. The incorporation of five distinct nanoparticles significantly enhances the effective thermal conductivity and energy transport capacity, leading to elevated temperature profiles. This improvement arises from the synergistic interaction of multiple nanoparticles, which promotes superior heat transfer pathways compared to conventional nanofluids.As M and Rd rise, EG and water base fluid exhibits superior and more dynamic heat transfer due to the enhanced thermal conductivity of water and its reduced resistance. Under the influence of magneto-radiative effects, EG-water enhances surface heat transfer. The findings of this study can be applied in various fields, as understanding transmission rates is valuable for industrial, environmental and biomedical applications including targeted drug delivery.
