The strongest determination is shown by MacDuff after he learns in Act 4, Scene 3, that Macbeth has caused his wife and children to be murdered. Macduff is determined to have revenge.
O, i could play the woman with mine eyes
And braggart with my tongue! But, gentle heavens,
Cut short all intermission! Front to front
Bring thou this fiend of Scotland and myself.
Within my sword's length set him. If he 'scape,
Heaven forgive him too.