Fiends (悪魔Akuma "Demon") are a monsterType consisting of cards resembling demons and devils, as well as many other vile, twisted, beasts or mischievous beings. Fiends receive a power-up from the "Yami" Field Spell Card, as well as more recently "The Gates of Dark World" and "Archfiend Palabyrinth". Since many Fiends are DARK, they also get a boost from "Mystic Plasma Zone". Many have effects that hinder or punish the opponent and many others require penalties from the user. Some Fiend cards work together while others Tribute themselves, other cards or payLife Points to use their effects. There are also a great number of monsters and spells that Summon Fiend-Type Tokens, which can be used either as Tributes or simple stall defenders.