While the mod has some enemies that are obviously female such as Ms. Female Monster Surprise: The mod has a "Female" enemy tag that is applied to both base game and Fiend Folio enemies to be used with the Sapphic Sapphire trinket.Developer's Foresight: As locking characters doesn't function properly in the Repentance API, trying to play as Tainted Fiend when he hasn't been unlocked through the regular means of getting Tainted characters will send the player to an unplayable sequence where Tainted Fiend is curled up inside Home's closet, but without the original Fiend to unlock him.Damage-Increasing Debuff: Introduces the status effect "bruised," which lowers enemy defenses.Most of it is snark written from Fiend's perspective.
Couch Gag: While the mod is loaded, the main menu has a faintly-visible piece of splash text above the options that changes every time the game is started or the player returns to the menu.Break the Haughty: The most prominent feature of Tainted Fiend is that his original Lovable Rogue personality is gone, replaced only with unending rage.The only thing that the item does is give you a +0.1 damage increase and an achievement.
Bragging Rights Reward: Getting the Your Eternal Reward item requires you to get all of the seven boss badges by defeating seven specific bosses with specific items, something that only can be done in The Gauntlet by following a specific boss order and not being able to buy any other items until later into the run.How that cob grew into everybody's favorite Lovable Rogue is anybody's guess. Bizarre Human Biology: Fiend is explicitly not Isaac, and is made of GMO corn.Biting-the-Hand Humor: A Binding of Isaac mod where one of the protagonist's defining personality traits is how much he hates the kid.Buster and his ghostly form will outright eat their mooks they summon before launching them at Isaac.Doesn't stop him from trying to kill you, though. However, since the horse was carrying a nuclear bomb, it explodes and reduces Meltdown to a skeleton. He'll even kill it when he gets low enough.