The only problem is that the targets don't know "omega" is last letter in Greek alphabet.
I consulted a dictionary for all the meanings of "Omega", wwh. The primary meaning is the one you have indicated. But another meaning is: "the last of a series, the end". (Ref. Random House Webster's Unabridged, 2001). The last post on a thread is certainly "the last of a series", wwh. If MY post becomes the LAST post on this subject ("Omegatist"), will I then become the author of my own rebuke? A fitting end, perhaps.