I played through EW and the Ivalice story, maybe these got answered somewhere and I missed it but, who created the Ascians and why can't the Garleans use magic?

Like in our world God made humanity and the planets, but in this world man made God, aka Hydelyn and Zodiark, so who made man aka the Ascians, I was hoping EW would have answered this and if it did then were at so I can go back and view those cutscenes/dialogue.

Why can't the Garleans use magic, I remember bits and pieces of the Goug people in the Ivalice story, it's been since SB so my memory is a little foggy, but did the Ivalice story or EW expansion say why Garleans can't use magic.