Heretic: Shadow of the Serpent Riders

Three brothers, known as the Serpent Riders, have used their immense magical powers to turn the seven kings of Parthoris into mindless puppets. The kings, in turn, led their subjects in doing the Serpent Riders’ bidding. However, the Sidhe elves are immune to the Serpent Riders’ spells and had no allegiance to any of the seven kings; the Serpent Riders thus declared the Sidhe as heretics and launched a campaign of genocide against them. The Sidhe were in possession of seven candles, each tied to a natural power of the world as well as that of one king.

Source: TheGamesDB