Tales of Kenzera: ZAU

An easy place to get this is at the beginning of act 2. After you head to the woodlands, you will make your way through a swamp. You’ll reach a workbench near your objective marker. Stop ant the workbench to make a checkpoint save. Immediately following this workbench is an arena fight with 4 small enemies. They are solar shielded, which means you can easily build meter with moon damage if need be.

Sit at the bottom of the arena and they will group up, then unleash your nova or beam. Once you get the achievement, you can quit to main menu and when you load back you should be at the bench, allowing you to try for the other one.