Are you talking about a moorish idol or a bannerfish? I got both when i googled wimple fish.
If its the moorish idol, no way. No one has success with them, especially not in 75 gal tank.
The bannerfish might do ok in there, but there are 3 different varieties and only one is reef supposably safe and im not sure how to tell which one is. Butterfly fish are really hard to keep, they are super delicate, not reef safe and I think they need a much more specialized diet than we can offer to keep them healthy.