Yes, the sentence you've provided could be considered a run-on sentence. A run-on sentence occurs when two or more independent clauses (complete thoughts) are not properly joined or separated. In this case, the sentence has multiple ideas and thoughts, but they are not effectively separated.
To fix the run-on sentence, you have a couple of options:
1. Split the sentence into two or more separate sentences:
- Donkey skin, the heroine, goes through many transformations of herself to overcome her father's evil desire of marrying her. This provides an optimistic outlook on incest for readers.
2. Use appropriate punctuation to separate the independent clauses:
- Donkey skin, the heroine, goes through many transformations of herself to overcome her father's evil desire of marrying her; this gives an optimistic outlook on incest for readers.
In both cases, the ideas are clearly separated, and the sentence is no longer run-on.
Note: In your question, you mentioned that you can't have run-ons in your essay. It's important to remember that essays typically require clear and concise writing. Therefore, it's advisable to avoid run-on sentences and opt for proper sentence structure to enhance readability and comprehension.