Place it right after the reveal in your edit, then follow it with Law and Order Dun Dun to underline the drama, or cut to DJ Airhorn when the moment turns into a celebration. Keep it as the reaction beat between the setup clip and the payoff, not buried under other effects.
Over dit geluid
A single voice stretches one long 'shii' across just over four and a half seconds, holding the sound steady instead of breaking it into words. It lands as stunned, amused disbelief, the kind of drawn-out reaction you give when something is too wild, awkward or impressive to answer straight away. It works because the stretch itself does the talking.