I'm fine with sacrifice. I'm not fine with him coming back despite it.
Especially since the Tyrant canonically has so many untapped armies of undead stashed in so many places (Ever heard of the Cenotaph?) that when he revives he'll be back to being a threat to the world in a matter of months at the absolute longest. And since his Phylactery is all but unlocatable And indestructible, he can't be put down permanently and he won't stop. Ever. Locking him down like the Last Crusade did is really the only feasible option, but that was a bit of a total fluke and he's unlikely to let such a thing happen again.
As written, the heroes have only really delayed and inconvenienced his world domination, not stopped it.