Ragaku

Ragaku (ラガクー) is the main antagonists who used to destroys the Gudo Tree and the fruits after the unknown human tribes attempt it.

Good Ragaku
When they not command by the leaders, they goes off to search the place peacefully before Agito shows up that Rouki learned he want to taste the Gudo Fruit too just like normal humans.

Evil Ragaku
The Ragaku's main objection to destroy the Gudo Tree and the fruits before Agito and the others shows up.