Hal Jordan's enemies: Hector Hammond

Hector Hammond was originally an easy-to-beat villain, but after more exposure to the meteor that gave him his power he became a substantially threat to not Hal Jordan, but the entire Justice League of America. After being experimented on by the Gremlins he has regained the ability to speak vocally (which he had lost due to the meteors effects). He has recently been possessed by the entity of Avarice, Ophidian.