Thank you very much for your help. Here are some more sentences I'd like you to check.

1)The Wildean dandy is on the one hand an aristocrat, who uses his wit to shock the others and on the other hand an individualist who seeks (demands) absolute freedom.
2) He devotes his life to the pursuit of pleasure which in its turn resulted from an indulgence in the beautiful. Actually, his only interests are beautiful clothes, talks, food and handsome boys.
3) Dorian is a young man whose beauty fascinates a painter, Basil Hallward, who decides to portray him. Dorian wishes he could stay young whereas the portrait grew old in his place.
4) While Dorian’s desire of eternal youth is satisfied , the signs of age and corruption appear on the portrait (are recorded/reflected by the portrait?) .
5) Dorian lives only for pleasure, making use of his friends (taking advantage of..) and letting people die because of his insensitivity. When the painter sees the corrupted image of the portrait, Dorian kills him.
6) Later Dorian wants to free himself of the portrait, witness to his spiritual corruption, and he mysteriously kills himself.
7) The portrait stands for the dark side of his personality, which he tries to forget by locking it in a room.
8) Every excess must be punished and reality cannot be escaped. Dorian cannot avoid the punishment for all his sins.

1) The sentence is grammatically correct, but there are a few minor changes that can improve the clarity. Here's the revised version: "The Wildean dandy is both an aristocrat who uses his wit to shock others and an individualist who seeks absolute freedom."

2) The sentence is clear and grammatically correct. No changes needed.

3) The sentence is clear and grammatically correct. No changes needed.

4) The sentence is grammatically correct, but the phrase "the signs of age and corruption appear on the portrait" could be improved for clarity. Here's the revised version: "While Dorian's desire for eternal youth is fulfilled, the portrait shows signs of aging and corruption."

5) The sentence is grammatically correct, but there are a few minor changes that can improve clarity. Here's the revised version: "Dorian lives solely for pleasure, taking advantage of his friends and showing insensitivity that leads to people's deaths. When the painter sees the corrupted image of the portrait, Dorian kills him."

6) The sentence is clear and grammatically correct. No changes needed.

7) The sentence is clear and grammatically correct. No changes needed.

8) The sentence is grammatically correct, but there are a few minor changes that can improve the clarity. Here's the revised version: "Every excess must be punished, and reality cannot be escaped. Dorian cannot avoid punishment for all his sins."