Halo Infinite

Choose Excavation Site, replay mission, on easy.

Walk up to the objective to trigger a cutscene and turn on the laser. Now, enemy drop pods will crash to the ground revealing some aggressive red melee brutes. Lure them into the laser by standing near it and using your grappling hook to change their angle of attack. If they stand close enough to the laser, they will die and this will unlock. You can melee them in the direction they need to go if they need a little extra nudge.

This achievement can be completed on the mission "Excavation Site." When you approach the objective marker at the hole in the wall, the banished mining laser will turn on. Brute berzerkers (brutes with no weapons that charge at you) will spawn in drop pods. You can sit near the laser (not too close because it will damage you) and they will charge to you. When they get close enough, melee them and the should back up close enough to the laser so it kills them. You will know the laser hit the brute because it will throw their corpse in the direction of the laser.

This achievement can be completed solo and on easy difficulty.

To get the achievement, start (or restart) the Excavation Site mission. Progress in the mission to activate the Paria's Extraction Laser, then lure a brute into the laser flux to burn it. Here is a video to help you.

This can be done on the mission "Excavation Site". You can get in a ghost, wait for a banished to hijack it and drive it into the laser. I found thus much easier than trying to lure an enemy into it.