1. Question:
* Are you only vain, also selfish, and...? (This makes it a question asking if someone is both vain and selfish)
2. Statement:
* You are only vain, also selfish, and... (This makes a statement about the person's character.)
3. Fragment:
* Only vain, also selfish, and... (This is a fragment that could be a part of a larger sentence.)
You need to provide more context or information about the intended meaning to get a fully correct punctuation and grammatically complete sentence.