Note how anon's name changes from お兄さん to 鬼威惨. Both are pronounced "onii-san", but the latter is a goroawase wordplay of the former, written by the kanji for "demon", "menace", and "tragedy" (they don't make any sense when put together anyway, so I'm splitting it up). This name signifies an abyuser, and can be roughly understood as a demonic onii-san. So here, it can be seen that anon has flipped out, and his inner demon calls the Deibu and its children out to the garden for an execution.
It's a common trope amongst the japanese Pretty much everyone uses it, notably there's a story with that combination in the title ( pool #1707 ) By the way, since you are so knoweledgeable, what do you think about adding to the site's wiki a dictionary of sort, where things like this are explained? It'd be very helpful