5 of the Hakaishin, Belmod among them, thought being hit by Beerus' Ki blast would've been fatal if not for Sidra's shield, and I highly doubt Belmod was the strongest amongst them when considering his feats and later scaling. That said, Beerus would win if managing to hit all three with one blast, but Belmod's imprisonment ball and Ki card combo seems to be far more damaging than his conventional abilities would suggest if Beerus was even unable to counter it. It's possible 3 Belmods using the ability would be able to deal enough damage to weaken Beerus and win.