Can you please check if these sentences are correct?

In particular, I'd like you to help me find an introductory sentence to my paragraph and a proper conclusion (with reference to the theme of the double).
1) Explore the theme of the double as it occurs in the works of the writers we studied in class.
2 First of all, I'd like to point out that we dealt with the theme of the double when analyzing novels such as Shelley's Frankenstein, Wilde's The Picture of Dorian Gray and Stevenson's Dr Jekyll and Mr Hyde.
3) As for Shelley's Frankenstein, both Doctor Frankenstein and his creature are complementary. Actually, they both suffer from a sense of alienation and isolation, both begin with a desire to be good but become obsessed with hate and revenge.
4) The creature stands for the scientist's negative self. He refers to his creature as a miserable monster, a demoniacal corpse and a detested form.
5) Though Dr Frankenstein initially flees from his creature, he is (will be) constantly oppressed (haunted) by the monster's presence. This oppression turns into a nightmare when he fails to fashion a mate for his creature.
6) In The picture of Dorian Gray, the picture stands for the dark side of Dorian's personality, his double, which he tries to forget by locking it into a room. The picture could be seen as a symbol of the immorality and bad conscience of Victorian middle class.

1 answer

For some reason the following sentence stopped me: Actually, they both suffer from a sense of alienation and isolation, both begin with a desire to be good but become obsessed with hate and revenge.
I suppose I was expecting a long "list" after the initial comma. Then I thought of 2 complete sentences. I'll leave it to you.

For the introduction, you might like to explain "doppelgänger" and the feelings/emotions that the very word evokes.

For the conclusion, have you drawn any "conclusions" from your study of this work? Many themes on this subject are depressing and this is no exception?

Sra