A song in Boku no Hero Academia season 3 episode 45 at 9:50 There's a song played for a short amount of time in Boku no Hero Academia season 3 episode 45 at 9:50. I think this song hasn't been played before in the series.

What is that song?
The Threat of Offense and Defense (脅威との攻防 Kyōi to no kōbō)

As another user pointed out, it has actually been played at least twice before! 


season 1 episode 10 at around 10:50
season 2 episode 3 when showing everyone on the minefield