Season 2 · Episode 16
Avatar: The Last Airbender
Appa's journey from being abducted in the desert to the present is explored.
When said as 'te arrepentirás' in a threatening context, it functions as a fixed warning phrase carrying an implicit threat, beyond its plain meaning of 'to regret'.
Literally 'to give nausea', but used idiomatically to express strong disgust or repulsion toward a person or thing, not necessarily physical nausea.
A very common fixed expression reinforcing total ignorance or incompetence. The 'ni' intensifies the negation beyond a simple 'no tener idea'.