starkii damsels r nice but he may just be mellow since he just got in. I have seen these several times and have always seen them attack tank mates and conspecifics as usual. I'd keep an eye on him.
i had one in my last reef and he was great i know not every one will be but i love his colors they are great and i only have a few fish so lets see what happens
They don't get as larger as some of the other damsels, usually 3"-4". They make good reef fish as they're non-aggressive towards inverts and other most. They're a good substitute for a pygmy Angel like a Flameback as you don't have to worry about them picking on corals.