Why all caps? Is it an acronym?
Because it's a scream, and all caps are a way to express screaming in text.
"Just remember ALL CAPS when you spell the man name"
"He write "VIK" in a sick demented handstyle" -Viktor Vaughn (another alias), Raedawn.
“DOOM, all capitals, no trick spellin'”
“Got what it take to get it through your thick melon”