In the Legendary Edition, this can be unlocked by using squad powers, tt doesn't have to be Shepard to use the power. Just as long as you command a squad member to use the power, it will unlock.
You can grind this out using one of the transit terminals at the Citadel. Use the power on the terminal when it's off cooldown.
Like all the power mastery trophies, it's best to have a squad that has all the powers covered, use them all on a transit terminal, then wait for the cooldowns to end and repeat until all the trophies pop.
This method takes about 30 minutes or so.