Which character has changed permanently because of the magic in A Midsummer Night's Dream?
Demetrius is the only character to have been left permanently changed by the magic within Shakespeare's A Midsummer Night's Dream. At the beginning of the play, Demetrius is in love with Hermia, much to the delight of her father, Egeus, who demands that the two be married. Hermia, on the other hand, does not return his feelings; she is in love with Lysander. Rather, it is Helena, a friend of Hermia, who loves Demetrius; unfortunately for Helena, Demetrius finds her repulsive.
This love triangle becomes further complicated when Puck intervenes, causing the two gentleman to abandon their interest in Hermia and instead focus on Helena. Hijinks ensue until Puck lifts the spell... restoring Lysander to Hermia and leaving Helena to enjoy her newfound love with the changed Demetrius.
In a stirring monologue towards the end of the play, Demetrius confesses that his love for Hermia has been replaced by a much more fruitful love for Helena:
...My love to Hermia,
Melted as the snow, seems to me now
As the remembrance of an idle gaud
Which in my childhood I did dote upon;
And all the faith, the virtue of my heart,
The object and the pleasure of mine eye,
Is only Helena.
Demetrius closes this speech by asserting that he "will for evermore be true to" Helena. The love of his past is now but a distant dream...