In "Act 5" of "Macbeth", what does Malcolm say about Macbeth and Lady Macbeth?
Malcolm says of Mabeth in Act V, scene 4 that his tyranny is creating trouble for him as he fights his war:
Both more and less have given him the revolt,
And none serve him but constrained things
whose hearts are absent too.
By this Malcolm means that people of both higher and lower rank are revolting against Macbeth and deserting from his army. The only soldiers who will stay with him are forced too, probably mercenaries, who fight only for the pay. Their hearts are not truly with Macbeth, so they will not fight as bravely. This continues a discussion begun between Malcolm and Macduff in Act IV, in which Malcolm's worthy qualities as a ruler are contrasted to Macbeth's tyrannies, foreshadowing Macbeth's defeat.
In the final scene in the play, Act V, scene 8, Malcolm repeats the theme of triumph over tyranny, referring to Macbeth as a "dead butcher" and Lady Macbeth as "fiend-like." He also reassures his followers they will be rewarded as order is restored in the land.
Malcolm, making the final speech of the whole play, says that tyranny produced
... the cruel ministers
Of this dead butcher and his fiend-like queen,
Who, as ’tis thought, by self and violent hands
Took off her life...
Macbeth's murdering ways make him a "butcher", though - as many critics have pointed out - the power of his soliloquys and poetic imagination make this a deeply reductive verdict which reminds us what Macbeth looks like if you don't hear his soliloquys.
And Lady Macbeth, of course, in this verdict has become what she asked the "spirits" in her first scene to make her become: a devil, a fiend, and one without remorse. This is, incidentally, also the first time we learn that Lady M has actually killed herself: we knew that she was dead, but not the how.
Hope it helps!