For anyone who cares for horses, Milo having to put down the poor horse that appears early in the film might count.
Aurelia and Severus dying hand-in-hand in the arena.
The ending. Rather than try the impossible task of outrunning the ash cloud, Milo and Cassia instead spend their final moments locked in an embrace. They kiss, just as the ash cloud engulfs them. The movie ends with their magma-encased bodies, still locked in an eternal embrace.
