In order to get this achievement the levels of all your learned abilities must equal 80 or greater.
Each officer has 4 abilities they can learn. Each time you learn an ability, it's level goes up by one. If 3 people have learned the potence ability, then you'll have potence level 3. In order to learn abilities, you usually have to kill a certain amount of peons or a certain amount of officers, and sometimes there is a time limit or other qualifiers, like don't use musou, or don't go below a certain number of attacks.
There isn't a set way to go about this, just pick characters you like and you'll get it eventually. You'll get this way before you max every ability, so don't worry about that.