What is a character sketch for Macbeth in Shakespeare's Macbeth?

Because we first hear of Macbeth in the wounded captain’s
account of his battlefield valor, our initial impression is of a brave and capable
warrior. This perspective is complicated, however, once we see Macbeth interact with the
three witches. We realize that his physical courage is joined by a consuming ambition
and a tendency to self-doubt—the prediction that he will be king brings him joy, but it
also creates inner turmoil. These three attributes—bravery, ambition, and
self-doubt—struggle for mastery of Macbeth throughout the play. Shakespeare uses Macbeth
to show the terrible effects that ambition and guilt can have on a man who lacks
strength of character. We may classify Macbeth as irrevocably evil, but his weak
character separates him from Shakespeare’s great villains—Iago in Othello,
Richard III in Richard III, Edmund in King
Lear—who are all strong enough to conquer guilt and self-doubt. Macbeth,
great warrior though he is, is ill equipped for the psychic consequences of
crime.

Before he kills Duncan, Macbeth is
plagued by worry and almost aborts the crime. It takes Lady Macbeth’s steely sense of
purpose to push him into the deed. After the murder, however, her powerful personality
begins to disintegrate, leaving Macbeth increasingly alone. He fluctuates between fits
of fevered action, in which he plots a series of murders to secure his throne, and
moments of terrible guilt (as when Banquo’s ghost appears) and absolute pessimism (after
his wife’s death, when he seems to succumb to despair). These fluctuations reflect the
tragic tension within Macbeth: he is at once too ambitious to allow his conscience to
stop him from murdering his way to the top and too conscientious to be happy with
himself as a murderer. As things fall apart for him at the end of the play, he seems
almost relieved—with the English army at his gates, he can finally return to life as a
warrior, and he displays a kind of reckless bravado as his enemies surround him and drag
him down. In part, this stems from his fatal confidence in the witches’ prophecies, but
it also seems to derive from the fact that he has returned to the arena where he has
been most successful and where his internal turmoil need not affect him—namely, the
battlefield. Unlike many of Shakespeare’s other tragic heroes, Macbeth never seems to
contemplate suicide: “Why should I play the Roman fool,” he asks, “and die / On mine own
sword?” (5.10.1–2). Instead, he goes down fighting, bringing the play full circle: it
begins with Macbeth winning on the battlefield and ends with him dying in
combat.