Tang eating my corals!!!! AAHHHHHHH!!!!!

So I have a really healthy White Cheek Tang that is killing all my green star corals as we speak! This isn't the first time he has done this. He first went after my pulsing xenias a few months ago and completely killed those. That in some ways wasent a bad thing because there was kind of a lot of them anyway, but I would have atleast liked to have isolated them and have a small colony of that. Now he has turned to my green stars and they are almost gone. I feed Mysis, bloodworms, brine shrimp, scallops, store shrimp, and algae sheets. Some of these items I feed more often (mysis) and some I feed less often (scallops, store shrimp). I try to feed algae if I remember. He grazes all the time, but has turned to less appropriate grazing items. My tank dose have a good amount of algae so he has some to naturally eat. For corals I have Pom Pom xenias (seems like he could go after these next), Kenya Trees, Frogspawn, zoas, mushrooms, SPS I forgot the name of, 3 pink bubble tip nems, and 1 green bubble tip nem (I think). My tank is 120 gallons and his tankmates include 1 Singapore angelfish, 2 Percula clowns, 1 male Blue Jaw Trigger, 1 sixline wrasse, 1 Yahsa goby. I am thinking if I put algae sheets scattered around the tank he will find those and it will be more like scavenging or forging. Just trying to see if anyone has a enter idea or something. Thanks!