How does Odysseus change by the end of his voyage?
Some things about Odysseus are notable because they do not change throughout all his travails on his journey home. They also form the backbone of his heroism so perhaps they are not supposed to change. His keen intellect which he uses to find ways out of trick situations time and time again, his great pride which leads him right into some of those situations, and his incredible strength and prowess in battle are constants throughout the journey.
It is perhaps his pride that, while remaining constant, undergoes the most change as he appears to be somewhat cowed by the constant trouble brought upon him by his unwillingness to appeas Poseidon and the death of so many of his crew because of his decisions.