Paracanthurus hepatus, commonly known as the Pacific blue tang or 'Dory', is a large surgeonfish which needs plenty of swimming space and clean water to thrive. It's rarely aggressive towards other fish, but can be towards other other tangs and food competitors. Once hierarchy is established it usually poses no problems. Just make sure it has clean water, enough swimming space and enough food.
Like other tangs, it will eat meaty foods, but it's important it can graze on algae/seaweed the entire day to ensure it will stay healthy. So feed flakes/pellets multiple times a day and make sure there is always seaweed available.