How do I defeat MacMorn?

Hint 1 of 5:

You will again need mighty strength.

Hint 2 of 5:

Defend yourself!

Hint 3 of 5:

Listen to his responses very carefully.

Hint 4 of 5:

Did he mention that you were dead already?

Hint 5 of 5:

Shift into a bear; attack him with sword; then invoke amulet.