Sentinels are flying guard robots that fire a continuous laser beam. They are the Monitor’s lackeys, so they help you on 343 Guilty Spark and The Library, but they are your enemies afterward. When they die, they explode and fall down, and the debris can sometimes hurt you.
Attacks: Continuous laser beam
Varieties: Non-Shielded- Don’t have an energy shield.
Shielded- Takes a bit longer to kill. You can tell if they have a shield when you shoot them.
Weapons to use: Plasma Rifle- Quickly takes them down.
Plasma Pistol- Use a charged-up shot or a few single shots.
Rocket Launcher- The explosion can take down several at once.