Fantasma Biancas (Italian for "White Ghost") are a species of perfect hollow/shinigami creation. Vizards are mostly Shinigami. Arrancar are mostly Hollow. Fantasma Bianco, however, are a perfect blend of both species. They do have zanpakuto-like things, but their technical name is Purifichi I Dei (Italian for Purify The Gods). They have a council that leads them, they have no real leader. The group is called the I Soldati Di Dio (Italian for God's Soldiers).
Main Article: The North
The North, also called Nrorxz in the Northite language (Northites were the species that dominated Nrorxz before the Fantasma Bianca conquered it, but their language is still used in three words: Nrorxz, Jouluu is the word for the Northite species, and Norzheim is the traditional word for Northern Skies, the Fantasma Bianca monestary that is their headquarters.
Main Article: Negativo Del Rory
Negativo is the Pope of Northern Skies, the headquarters of the Fantasma Bianca. Therefore, he is the ruler of the species.
They believe in a warped version of Christianity, called Soldatism. In their Bible, it preaches that Fantasma Biancas should fight to live, and that if one dies, it is shameful beyond their years. It also teaches that Godrik, their God, will come down from Heaven to kill everything. The Fantasma await this day as Ragnarokk II.
Unlike Xiāochú, they were born a complete hollow/shinigami fusion, and over time a group of Fantasma Bianca devolved into hollows and shinigami. A Xiāochú is a fusion of Arrancar and Vizard. I just thought it was important to point out the difference, so whoever made those, don't scold me.