Enel is the main antagonist of the Skypiea arc. He is the former "God" of Skypiea. 
 

Sky Boss Gedatsu (空番長ゲダツ, Sora Banchō Gedatsu), the third priest, punishes criminals with the Ordeal of Swamp
 

Satori of the Forest (森のサトリ, Mori no Satori) punishes criminals with the Ordeal of Balls.
He is the older brother of Hotori and Kotori. His ordeal has a 10% chance of survival.
 

Skyrider Shura (スカイライダー・シュラ, Sukairaidā Shura), the second priest of the Upper Yard, punishes criminals with the Ordeal of String. He tangles his enemies in nearly-invisible and unbreakable string and then attacks with his lance named Heat Javelin, that has a Heat Dial inside. He rides a flying monster bird named Fuza, who has a Flame Dial in its mouth that allows it to breathe fire

Gan Fall (ガン・フォール, Gan Fōru), is the current, two time God of Skypiea. He was formerly known as the Knight of the Sky (空の騎士, Sora no Kishi).
 

Bellamy the Hyena is the captain of the Bellamy Pirates, who ruled over Mock Town. He has a bounty of 55,000,000. This bounty has earned him a secondary nickname as the "Big-Time Rookie". Bellamy is the main villain of the Jaya arc.
 

Crocodile was the president of the secret criminal organization, Baroque Works, and the main antagonist of the Baroque Works Saga. His codename in the organization was "Mr. 0". He is the longest running primary villain of the series as well as the first villain to hand Luffy a complete and utter defeat. He was originally introduced as a Shichibukai but was stripped of his title after attempting to take control of the desert kingdom, Arabasta. He was first introduced as a major enemy of Luffy's, however, the two later formed an uneasy alliance during their escape from Impel Down and the latter half of the Battle of Marineford.