It's actually pretty annoying that the word "Block" doesn't appear when you block an attack in this private server. :P
I played Luna online ( gpotato) and as everyone probably knows, "block" appeared when you blocked an attack :P
I'm sorry to say this mate but that info is not legit, because that purple cloud is just a mark that you get hit. I get the purple clouds on my destro and entrapper.
Sorry T.T