[Perodogo]

Well I don't know about wrasses, but I can tell you that you can mix angels, particularly if your tank is big enough. I have 9 different angels in my 500 gallon tank and while they would prefer to be alone, they don't go out of their way to hunt each other out. I've had some of them together for nearly 4 years now. Adding another angel in your tank should be okay as long as you don't add another juvenile angel that has similar patterns with your emperor (i.e. blueface angel, majestic angel, koran angel, etc.). Your clown trigger could be an issue though although mine is behaving (but then again, he's only 4"). Good luck.