How is heroism and villainy presented in Macbeth?

Heroism and villainy are presented in Macbeth through the character of Macbeth himself.  When the play begins, Macbeth is shown as the main conquering hero and savior of the battle.  

For brave Macbeth--well he deserves that name--Disdaining fortune, with his brandish'd steel,Which smoked with bloody execution,Like valour's minion carved out his passageTill he faced the slave;Which ne'er shook hands, nor bade farewell to him,Till he unseam'd him from...

Heroism and villainy are presented in Macbeth through the character of Macbeth himself.  When the play begins, Macbeth is shown as the main conquering hero and savior of the battle.  

For brave Macbeth--well he deserves that name--
Disdaining fortune, with his brandish'd steel,
Which smoked with bloody execution,
Like valour's minion carved out his passage
Till he faced the slave;
Which ne'er shook hands, nor bade farewell to him,
Till he unseam'd him from the nave to the chaps,
And fix'd his head upon our battlements.

Macbeth is brave, strong, and violent.  That sounds exactly like any modern day hero that I can think of.  Duncan thinks that Macbeth is such a worthy man that Duncan gives him a second thane title and invites himself over to dine with Macbeth.  

Unfortunately, Macbeth is not as pure as the driven snow.  He is capable of great villainous acts.  Most notably is his murdering of Duncan.  Murder is bad enough, but a plot to kill a decent man (who happens to be king) is awful.  Then Macbeth just spirals out of control.  He starts to kill anybody and everybody who might have a claim to his throne.  That's villainous.