Who is the great Holy Knight?
Great Holy Knights「聖騎士長, Seikishi-chō」 are the most powerful of the Holy Knights, and possess the authorities of commanding over them, thus making them the leaders of the Holy Knights. This gave previous Great Holy Knights of Liones, Dreyfus and Hendrickson, command over the whole country after the coup détat.
Does Gowther end up with Guila?
She became lovers with Gowther after the defeat of Hendrickson, but it was revealed to be due to Gowthers brainwashing. When Gowther released her from his brainwashing, she forgave Gowther as she able to remember her father more clearer than before.