SteamWorld Heist II

A Crewmate's active job can be switched at any time by changing their equipped weapon. If a Crewmate's job is changed, they can equip abilities from any leveled Job with Cogs

To earn this achievement, switch one of your Crewmate's jobs and activate the Ability of their previously leveled Job. For example, give a Sniper Daisy a rocket launcher to turn her into a Boomer, then activate a Sniper ability in her character menu