Answer:
Rufus Wilmot Griswold. He just thought that he was better than Poe.
Step-by-step explanation:
The rivalry happened when Griswold succeeded Poe as the editor of a magazine - and Griswold was being paid a higher salary than Poe. Griswold even wrote negative things about Poe when he died and it was not a positive obituary. He wanted to harm Poe's reputation. Griswold thought he was the expert and not Poe. He was known as a critic of Poe and his writings.