Put it just before the reveal in a bait edit, so the fake callout sets up the payoff. Follow it with a vine boom when the joke lands, then cut to the reaction shot. For a bigger fakeout, place a dramatic dun dun dun cue ahead of it and let the ult call close the sequence.
About this sound
This short imitation of an enemy Raze ultimate callout delivers a sharp, urgent voice line that sounds like danger is about to land. It creates instant tension and a jolt of panic, even for players who know it is not real. The fake callout comes from Valorant, where Raze is an Agent, and it works because the line is so recognisable to players.