Deep Sky Derelicts: Definitive edition

This is easiest to get in the starting, level 1, location. Explore the derelict enough and you will come accross a few battles with some very weak enemies. You want 3 vs 2, then with one of your guys use an attack that hits both enemies, then use strong attacks with the other two and they should go down quite easily without ever getting an attack in, unlocking this.