Deckard Cain

Major and recurring fictional characters from the fantasy series Diablo are listed below, organized by respective origin within the fictional universe. The story of the Diablo series revolves around events of the Great Conflict, a war between denizens of the Burning Hells and the High Heavens. Specifically, the games focus on events within the mortal plane, called Sanctuary, which are collectively known as the Sin War. The series began with Blizzard Entertainment's 1996 video game Diablo and has been expanded with the sequels Diablo II in 2000, and Diablo III in 2012. The franchise has been further extended with a number of novels, most written by Richard A. Knaak.

The lead world designer for Diablo III is Leonard Boyarsky, who has done notable previous work on Fallout.

Creatures from Diablo's Burning Hells are called Demons and the most powerful seven of these demons are known as the Great Evils. These elite can be further broken into two groups: three "brothers" called the Prime Evils and four somewhat less powerful demons called the Lesser Evils. All of the Great Evils were eventually absorbed into the essence of Diablo when he became the singular Prime Evil in Diablo III.

Sometimes known simply as the Three Brothers, the Prime Evils are revealed very early in the original Diablo to be the rulers of the Burning Hells and leaders in the fight against the forces of Heaven. However, prior to the start of the first game, it is shown that all three have been exiled to the world of Sanctuary by the Lesser Evils, where they retain very little of their former power. This of course makes Diablo, and in the sequel his brothers, accessible to the player's mortal character as a final challenge in certain chapters of the games. Despite being nicknamed the "Brothers," there is no mention of the Prime Evils having parents and indeed are often said to have existed "from the Beginning," though they are given different, but unquantified, ages.

Diablo, the Lord of Terror (voiced by Bill Roper, later by J. B. Blanc), is the titular character and main antagonist of the game series. He is also the youngest and most powerful of the three Prime Evils. Diablo and his elder brothers Mephisto and Baal ruled over Hell as a sovereign triumvirate until overthrown by the Lesser Evils Azmodan and Belial, who banished the Prime Evils to the mortal world of Sanctuary. However, Diablo's game manual implies that the "Dark Exile", as this became known, was in fact intended by the Prime Evils in order to corrupt the mortal world personally. A mage order known as the Horadrim was formed to hunt down the Prime Evils and remove their corruptive influence from the world of men. Diablo was the last of the Prime Evils to be captured by the Horadrim, and his red Soulstone was buried in a series of caverns over which a monastery was built, which later became the Cathedral of Tristram.

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Wikipedia