Place it just before the defeat lands in your edit, then follow it with the Womp Womp Fail Sound to confirm the loss and the JoJo To Be Continued cue to leave the next attempt hanging. Keep it as the reaction beat between the bad setup and the outcome, not as the opening or the ending.
About this sound
This is a short Japanese voice line, lasting about two seconds, in which a character asks in a fast, strained voice how they are supposed to fight in their current state. The rising, disbelieving delivery makes the panic feel abrupt and funny, turning a hopeless setup into a relatable joke. It works as a general anime reaction line, understood through its tone even by listeners who do not speak Japanese.