Board Thread:General Discussion/@comment-4504826-20160426040035/@comment-26242189-20160427001630

Imma Quote the wikia real quick:  The death sound is heard from off screen, and the protagonist's EXP is set to 99999, granting them LV 20 (regardless of their EXP before the encounter – in normal playthroughs, it will always be 50000).

EXP stands for EXECUTION points.

Which shows how much you KILLED.

MEANING SANS IS DEAD.