Place it right after the reveal shot as the first reaction in your edit, then follow with an oh my god wow button for a second stunned voice, or lead into it with a sudden suspense button to build anticipation before the payoff lands cleanly.
Über diesen Sound
This is a short voice clip built around a single drawn-out 'Woahhh' exclamation, stretched over a few seconds instead of said quickly. It gives listeners that stunned, impressed feeling of seeing something bigger, faster or wilder than expected, with the amazement landing in the long hold on the word rather than in any extra lines or effects.