To confuse by using methods which are themselves confusing. An example of a confusing method by which someone might fazniah is the method of multiple negatives: eg. I'm not sure if I'm uncertain about your non-use of what I think you don't perceive to be the incorrect non-formulation of what you didn't say I thought, I don't think.
Someone or something which exists only for the purpose of magnifying confusion in a situation.
My master plan is in disarray from that move that Mark pulled on me when he chose to fazniah my colonel burton.
Why does that fazniah keep circling his mig jets over my mobile construction vehicle without firing on- oh crap it was a distraction! No wait, now they're moving-no, wait... Nevermind, I'm too confused so I better just surrender.