Character Change of Macbeth

I have this giant 2 hr exam nxt week. 15mins will be on Macbeth.

I have a last year exam paper with this question I will like to answer if it comes up.
'"Describe how a character changes in the text. Explain how this change helped you understand an important idea in the text."

My answer is that Macbeth becomes more ambitious and greed for power after meeting the witches.
But... I am kind of stuck on the 2nd part of the question.

If anyone could help, I appreciate that and a big thank you too.

Ambition and greed makes Macbeth vulnerable to his wife's temptations to betray and kill his king. Having murdered Duncan, Macbeth kills and kills to survive.

Perhaps, he should have killed even more - Macduff for instance before he fled Scotland. But his conscience bothers him too much, at first - the reverse of his wife.

For Macbeth, ambition and greed soon take second place to survival, whereas, his wife suicides.