If you want to change the text used when a specific enemy or player character dies, you have to change the text used for the Death State. There are separate messages for both.
If you want to change the text for when you defeat all enemies and win a battle, it's in the Scripts. In "Vocab" under "Battle Ending Messages".
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Okay, I rolled a 14. What's that mean? Hsu
That you're a cheater. This is a 12-sided die. Chan