The dependence of the subduction regime on 3-D slab geometry poses a challenge to achieving an accurate estimation of the evolving thermal structure of megathrusts globally. While slab dips and ages have gained attention, the specific impacts of oblique subduction remain unmeasured. Here we present an integrated thermal model that quantifies how slab morphology can shape the thermal state of megathrusts such as that in Makran subduction zone. The model considers both slab obliquity and depth variations along the trench. We find a considerable match between slab petrological dehydration zone and the distribution of historic great interplate earthquakes. We suggest that, the accumulation of fluids along the megathrusts by slab metamorphism can foster a more polarized circumstance for the decrease of plate coupling and increased interplate ruptures. It is thus imperative to improve model representation and more realistically represent how slab geometry drivers affects the metamorphic transitions and earthquake occurrence at megathrusts.

thermal regime, slab dehydration, earthquake, 3-D model, Makran subduction zone