Why did Griffith rape Casca?

Griffith and Casca are both characters in the famous Japanese cartoon Legend of Sword Wind. He has deep feelings for Gus, the hero of the comic book, and he also admires and appreciates Gus. However, because Gus left later, his heart gradually changed. Later, when he saw two people hugging and comforting each other, his heart became more resentful, so he wanted to rape Casca to get back at Gus and satisfy his deepest dark desire.

In the golden age, Gus and Kaska longed for Griffith, which paved the way for their later love. And Griffith has deep feelings for Gus. He once said that among many people, only Gus can temporarily forget his dreams, so the bond between the two people is also very deep, which is why Griffith will be hit like this after Gus leaves the Eagle Group, and he will be disabled. However, Gus came back to save himself at this time, which also deepened his resentment.

Casca once liked Griffith, but in order to please her, he took her as the object of buying off Gus. When he was rescued, he saw the hug between Casca and Gus, and he also saw the feeling he longed for, which he could have, so he tried to sleep with Casca. So after the sacrifice, he became stronger, so it was also an opportunity to get back at Gus, so there was the plot of raping Casca. All this is just to express my strong feelings for Gus and my hatred of leaving myself.

Griffith is a poor man, but he is also hateful, which is why Gus embarked on the road of revenge and Casca fell into a coma. Everything comes down to his own feelings for Gus and Casca. Without this feeling, there will be no subsequent plot.