A Sangheili named Marikos is informed that the human's chaingun turret can't angle up high enough to shoot down enemy Banshees... so he rips it off its hinges, blows some Banshees out of the sky, and proceeds to carry the thing around like nothing for the rest of his time in the campaign.
The Brute-controlled Scarab getting shot in the face point-blank by artillery cannons, right after the Chieftain leading it bragged about beingunstoppable.
The method that the humans use to kill another Brute-controlled Scarab.