This page in our guide to Control contains the description of the battle with one of the bosses, Mr. Tommasi. Defeat him to unlock a trophy/achievement of the same name.
Where to find the boss?: You encounter Mr. Tommasi during one of the story missions. The opponent will escape. However, at the end of the game, he will become active again. Talk to Emily Pope near the end of the game and you will get Mr. Tommasi quest
Description: Head to the Turntable location - you will see that the once closed large gate leading to the new area has been opened. Use levitation, launch off the bridge and fly towards the marker on the map, which leads to the boss. You reach Stealing awe location - this is where you fight with Mr. Tommasi.
The fight can be really challenging. The boss flies around the arena and sometimes throws projectiles at you. Simply hide behind the large stone in the center and shoot the enemy. Pierce works great here - it destroys the enemy's Shield and deals him damage. You should also use telekinesis to throw objects, but the boss dodges a lot - try to perform quick throws, don't wait for the object to appear near the heroine.
When Tommasi loses a little bit of health, he will be joined by flying and exploding beasts. Be sure to use focus on them and try to kill them as soon as possible. Be careful while you are focusing on the beasts and stay out of the sight of the boss.
When the boss's health is low, a vanishing creature will appear. The enemy is possessed by The Hiss - if you get hit by it, you can die. From now on stay on the move, perform dodges and try to kill the monster or kill the boss as quickly as possible.