Rare-earth elements dominate both the industrial and the medical fields. Recent advancements in assisted bone healing implant research have sparked a revolution emphasising the exploration of new materials and customized applications with simplified methodology. In line with this trend, our study introduces an approach by applying a rare-earth element, terbium, as a coating on magnesium alloy implants. The in-vitro behaviour of the coated implants was systematically evaluated based on the duration of the coating formation and optimised. The TCC-30 coating started to degrade beyond the optimised duration of conversion. The resulting coating exhibited a distinctive nanolamellar structure on the surface, which transformed into a flower-like morphology as it matured. The chemical profiling of the coating with XPS confirmed the presence of elements including Tb, O and Mg. The mineralizing ability was examined with simulated body fluid (SBF) and Dulbecco's Modified Eagle Medium (DMEM) was found to possess nano-agglomerate structure in the form of clusters and coral-like morphology with nano petals structure, respectively. Further exploration of the biological behaviour including monitoring cell attachment and proliferation demonstrated enhancement. This innovative approach holds promise for enhancing the performance and biocompatibility of magnesium alloy implants, marking a significant stride in the ongoing evolution of assisted bone healing technologies.