In battle, Gut's could normally be counted upon to not pay attention to much of anything that wasn't on the down end of his sword. Some people (Casca comes to mind first) would call it mindless brutality but it was that laser focus that let him fight so effectivly.

And Sion now had the lovely pleasure of having that murderous focus upon him.

"Shut up." Words, words meaningless, useless. There's nothing Griffith can say that would change this. He rushes forward unheeding. His blade is deflected by Sion's sword but he barrels through, trying to push the slimmer man over. If he is hurt, so what. He lost an arm to his friend. He lost an eye. He lost his dearest friends and the only person he ever thinks he ever managed to love. He lost his whole life. What more could Griffith even do.

"Shut up shut up shut up! You and your fucking kingdom! What right did you have! What right!!"