As far as I know from the game, the "good" factions are the Sylvan, Haven, and Tower; the "neutral" factions are the Barbarian, Fortress, and Conflux; and the "evil" factions are the remaining ones.
When you enter the altar of sacrifices, the "evil" factions can only sacrifice creatures for experience, the "good" factions can only sacrifice artifacts, and the "neutral" factions can sacrifice both artifacts and creatures.
Auto-translated
