The Fourth act opens and ends with Bottom at center stage. How might he be the opposite, of Theseus' character?
Bottom is the kind of character we meet once in a while in our lives -- the attention-grabber, the "me, me, me" kind of person -- it is all about "me". He wants to be everything in the play, Pyramus and Thisbe, but is quickly shut down by Quince, who is a very good reader of his actors' skills and limitations. Theseus, in some ways, is also a "me" kind of guy, but only when it comes to Hippolyta. Theseus wants only Hippolyta to orbit around HIM, while Bottom wants the entire world's attention. Also, Theseus is at the top of the social scale in Athens, while Bottom is truly "at the bottom"; an actor, which in Shakespeare's day was not a very reputable profession, plus he is a weaver, which is a tradesman -- again at the bottom of Shakespeare's social world.