An excellent step by step (as usual) and an unusual fly. The title threw me completely. There is a Butcher salmon fly. The details are here, There is also the Bloody Butcher a wet fly for trout and sea trout. I don't have a picture of a Bloody Butcher in my collection but here is the original Butcher trout fly, the Bloody Butcher uses a dyed red hackle in place of the black at the throat.
Your fly was not at all what I was expecting when I saw the title.
"Political correctness is a doctrine, fostered by a delusional, illogical
minority, and rabidly promoted by an unscrupulous mainstream media, which
holds forth the proposition that it is entirely possible to pick up a ****
by the clean end"