The Tower Keeper is a Hardmode boss that resembles a large humanoid being with no lower-body and is composed of rocks and geodes. It is currently the mod's only hard mode boss.
The boss can be summoned with the Pocket Cursed Mirror. Alternatively, if it has yet to be defeated in the world, it can be summoned by smashing the Cursed Mirror (located in the top of The Cursed Tower) with a Stone Hammer. It is recommended to fight after the boss before spawning with Pocket Cursed Mirror.
- The Tower Keeper will follow an attack pattern that will repeat for most of the fight and follow this specific order:
- First, The Tower Keeper will hover towards the player.
- It will then go into a "Halt Phase" in which it will regenerate 0-10 of its Protective Stones if any were destroyed.
- Then it will charge towards the player 6 times in rapid succession.
- Upon reaching 50% health, Protective Stones will no longer respawn. However, it will still go into it's "Halt Phase".
- Upon reaching 30% health it will begin to fire Geode Spikes in the direction of the player, this attack replacing the 6 rapid dashes.
- Upon reaching 15% health, it will regenerate one more ring of Protective Stones becoming completely invulnerable until all Stones are defeated. During this it will break it's original attack pattern and instead remain mostly stationary occasionally moving a little in the direction of the player. It will spawn an endless wave of Geode Spikes both rising from the ground and falling from the sky in the area around the boss while continuing to shoot them towards the player.
- It's health is increased from 9000 to 11000.
- Like The Cursed Tower, the boss has two color variants. One for both world evils. (Crimson and Corruption) However, this is simply aesthetic and doesn't change the difficulty of the fight. The boss' colour is decided depending on which evil the Pocket Cursed Mirror or Broken Mirror used to summon the boss is based on.
- Furthermore, the Geode Spikes in the fight are akin to the color of The Tower Keeper.