Snorvich.
Thank you for your post. We understand your desire to add an Emperor Angelfish to your aquarium. We recommend proceeding with caution given the contents of your tank. The Emperor is known to nip at stony and soft corals (sessile invertebrates) and clam mantles, but possibly could be kept with small-polyped stony corals and somewhat noxious soft corals.
Pat S.
LiveAquaria
Drs. Foster and Smith