Call of Duty Black Ops 3 - Rolling Heavy Achievement/Trophy Guide
In the safehouse, buy and equip the upgraded the Unstoppable Force under the marshall core. This can be done in any mission but is easier done in Mission 4: Provocation. About halfway through the mission you will come to a courtyard and if you run to the back there will be 5 robots that spawn, stick together. You'll want to run up to them and use your charged cybernetic ability to kill them all in one charge. If you fail cook a grenade to kill yourself and try again.