I disagree. Jesus spoke of Satan as an actual being.
A keyword search of Satan revealed quite a number of references to him and his activity.
https://www.biblegateway.com/quicksearch/?search=satan&version=ESV&searchtype=all
Personification, according to Webster:
1. attribution of personal qualities; especially: representation of a thing or abstraction as a person or by the human form.
2 a divinity, or imaginary being representing a thing or abstraction.
Calling Satan a personification of vanity does not disqualify him from being an actual being. Instead it means that vanity is the poisoned spring from which flows all his other evil. It is what makes him the king of evil, ruling over all other evil.