Start a 1v1 on Blood River, standard mode, Normal AI, set their AI leader as Arbiter and set yourself as Cutter. Build up your base and army as you normally would, wait for the AI voice to say they're going to attack your base. When they do, start killing his troops only. He will try to use his Rage on your base, army and grandmother. When he does, just drop a Disruption Bomb on him. If it doesn't work, kill him, let him come back for more and drop another Disruption Bomb on him. Rinse and repeat until you have the achievement.
Start a 1v1 on Blood River, standard mode, set yourself as Cutter and your friend as any Covenant leader. Meet each other in the middle of the map, get your friend to use his power and then you drop a Disruption Bomb on him. Rinse and repeat 4 more times and the achievement is yours.