This phrase is used when someone overcomes a problem or a situation that was causing them trouble or harm. It literally translates to 'Did you kill the one who was killing you?', but it is not about actual killing. It's a metaphor used to express that you've dealt with the issue that was bothering you.
Examples
- Spanish: Finalmente, dejaste ese trabajo que te estaba haciendo infeliz. ¿Mataste a quien te estaba matando, eh?
- English: Finally, you left that job that was making you unhappy. You 'killed the one who was killing you', huh?