Its a take on the term "blah blah" which we use when we are tired of hearing the same bullshit over and over again in real life. fblah fblah is basically being sick of hearing someones self riotous self help rhetoric they post on Facebook

Someone who is possessed by clout chasing. The original human is now gone and a demonic entity that feeds on clout is all that is left. An empty shell with no control of their actions, forced to blindly react to situations they think will bring them attention.