Is the damsel or Wrasse aggressive to your clown? Also the Lunare Wrasse
is a fairly aggressive/large fish and should not be kept in a 55 gal IMO
. More then likely the clown is stressed either due to sickness or aggression issues. I would QT him for observation
and to separate him from your other aggressive fish for awhile. If you plan on making this a reef or getting inverts then I would return the wrasse. Even if you do keep him it will need a larger tank in a couple of years.
Edit: From your previous post you mention a Kole Tang having issues
and battling a bad algae breakout.
Since you only mention 3 fish I assume your Kole passed. Posting your water parameters ie: nh3
/temp & po4
if you have that test would be helpful as well to try to get these issues resolved.