as has been said, most damsels can be little buggers, damsels are great feeders and thats about it, although a few like the fiji blue devil damsel with the bright orange tail are usually pretty mellow, and yeah, damsels are classified as anemone fish... your anemone should accept freshwater mysis shrimp, snapper, and any ofter smelly meat from your local seafood deli,
Its up to you, but I would take apart the tank, catch the damsel, and find it a new home...

new home: My stone fish says "In my belly" (fat bastard accent needed)