Don't get me wrong shere khan is a very manipulative powerful villain but in the end he's just a strong tiger in one of the ways he died from a fire around 800°C While Tai Lung was using Blue fire to fight and he was handling it fine (Blue fire is 3000°C )
W edit but I feel like Durabillity goes to both because tai lung tanked hits from Po and got smashed into othe building and shere khan survived fire and falling from a great height