Macbeth
Macbeth the Thane of Cawdor, Thane of Glamis and king repeated the weird sisters on [line 50]. Macbeth has had many diffrent personalities. Originally he is so loyal he could go off on dangerous trips for the king. But the lure of power changes him into what one could call a monster. Macbeth completely abuses his power as king in order to maintain control. Emboldened by the prophecy from the witches he behaved without regard for others, eroding his support. This was his downfall because he felt that he was so powerful and needed to maintain his power by any way possible that he disregarded his responsibility to his wife, kingdom, and friends. He died alone and in line with the prophecy.
Like Macbeth Lady Macbeth was once satisfied with pleasing the royal highness. As soon as she found out the prohecy she changed her responsibility of being a nice house warming house wife into a woman hungry for power and determined to exercise the power she had over her husband to bring it to pass.
It seems to me that she feels responsible for Macbeth's future as she tries to convince Macbeth to take power. In the entire act 1 scene v Lady Macbeth argues to Macbeth why he has to kill Duncan. Later on the power in the play starts to shift as the weight of her responsibility for all the death starts popping up as images in her head in act V sene 1. As a result her culpability tragically got the best of her.