It looks to be a juvenile imperator {aka emporer} angel,it will grow to over a foot in length and needs a very large tank.It is generally not reef safe. It can be kept with caution,w/ certain corals however.
It should be fed angel preparations {formula 1 & 2} mysis shrimp,krill,spirulina,algae sheets or nori,and have plenty of LR on which to graze.Blood worms would not be a good choice IMO.
How long have you had him? What was he eating before?