Alright, so focalors created a human clone with no memories and basically gave it 0 instructions other than "lol just act". Furina back then didn't stutter and spoke very well, but then the retarded fontainians thought this wasn't "god-like" enough so she came up with that actor persona. Yeah in the end it's the fault of Focalors for not showing some divine prowess to the masses before switching to furina - they look the same, nobody would notice. Also the people in fontaine are just generally retarded, but this was always known.