FF16 expansions/DLCs in the work? How will this affect FF14?

[Ransu]

No, he never said that. He said that the "price of this boon" was the pall that descended. This could mean anything, like other jealous gods cursing their land. Before you say "price of this boon" obviously means that it's the direct result of using magic, you should note that people use that kind of phrase to mean indirect effects as well, like someone saying that "the price of our pride is to be banished from the realm"; that doesn't mean the pride literally banished them but that their pride incurred the wrath of someone who banished them.

Ultima:
"We visited upon it a miracle-magic. And in its light did all life flourish.
"Yet the price for this boon would prove heavy."
"A pall descended upon this land, painting the horizon black as night"

And Joshua LITERALLY follows up that scene with "If magic caused the blight, then what of the mothercrystals" which we later find out their purpose to cast the powerful raise spell to recreate the world.

Ultima literally spells out exactly what the blight is. The use of magic caused the blight because the blight is the result of depleted aether, which again, is why all plant life dies and the soil turns black and its why you can't use magic in blighted areas as there is no aether there.