NOTE: PLEASE READ ALL PAGES BEFORE POSTING. Repetition is starting to become a real issue on this topic... This is a suggestion for a new boss. This idea came to me from a thread about the lack of actual skill needed to beat bosses. Simply put, you would fight yourself, only a darker version. They would have something akin to Anti-Armor, which would be a dark version of the Hallowed Armor. The whole concept would share similarities with PvP, only in singleplayer. Anti-Players would be much stronger and faster than normal players, even with a full set of Hallowed Armor equipped. This would implement a need for skill to beat such a tough enemy. The actual battle could span entire maps, and could be fought in any biome. Anti-Players would have the ability to use Anti-versions of all the weapon types in the game. I'm thinking they would be able to use them in stages depending on how low their HP is. For instance, they can only initially use a basic anti-sword. After a bit they start using guns, and so on. At lower health, they are at their strongest and fastest, and can use anything from anti-flails to an anti-breaker blade. The Anti-players would be controlled by an advanced NPC system, superior to any seen before in Terraria. They wouldn't just act like humans, you'll believe they're humans. Let me know what you think. And yes before anyone says anything, I know this is horribly cliche for videogames, always fighting a copy of yourself. But I think it would work nicely with Terraria. Edit: You can only fight them in singleplayer mode. This prevents easy kills. Edit 2: Name updated to Shadow. Edit 3: This is Xrizux's take on the animation and the beginning of the battle: Edit 4: Stickynote's rendition of an Anti-Ore: Edit 5: Shadow drops Dark Matter, which is used to make Anti-Weapons/Armor/Etc. Shadow does not mirror your movements; he has is own AI. In multiplayer, Shadow's Summon item, All's End, will summon The Shadow Legion. Shadow fights you with Anti-Version's of your current inventory. For example, if you have any sort of sword, Shadow fights you with an Anti-Sword. Shadow's stats increase each time you defeat him, making him progressively harder.