Hi,
From my experience, your Purple Tang won't be boss for long
I have a Powder Blue for over four years and a blue streak cleaner wrasse for almost five. When I first got my PBT it have severe Ich and was under nourished(rescued) I fed lots of Mysis (the person I got him from had his tank on a strict Nori diet??) and the Blue Streak cleaned him up really well. Never had Ich since.
As others have said, feed garlic based foods. Cleaner wrasse are hit/miss, but mine has helped me a lot. QT is also a great idea with new additions
You're going to like the new boss.