I got this achievement while going for the one listed at the bottom of the solution, I would recommend going for that one and getting this one at the same time. But here is a guide for this achievement specifically.
To get this achievement you will have to unlock a few things first before you can get it the easy way.
First what you will need to do is play the campaign and complete the prolog along with tournaments 1 - 5.
Once you complete tournament 5 you will unlock the playable character Mackenzie. This Robot comes pre-equipped with the Attack Harmony augment.
Once Mackenzie is unlocked, I selected tournament 1 because it was the easiest while also selecting to play as Mackenzie.
Find another bot to fight.
Fill your attack cells to the same power 1/1, 2/2, etc. (with harmony augment when the power cells are the same the attack will be doubled)
Once you attack the achievement is yours.