Mastermind (Boss)

"You feel that your mind goes numb..."
The Mastermind is a Hardmode boss and is the mechanical counterpart to the destroyer. HOWEVER, this guy requires Rotten Chunks, while the Mechanical Worm now is crafted with Vertebrae. Note: BOTH can spawn in a world without Crimson (For Destroyer) or Corruption (For The Mastermind).

To see strategies on defeating the Mastermind, see Guide: Mastermind Strategies.

The Mastermind is INVINCIBLE during the First Phase. To defeat the First Phase, you need to defeat such named Crimtane Probes. You have to defeat ALL of them. If you do this and you're in Expert Mode, prepare for a lot of quick attacks.

Second Phase
In the Second Phase, the Mastermind gets vulnerable to any attack. Unlike the BoC, it actually continues spawning its minions. In this case, Crimtane Probes. It charges through 6 attacks.
 * 1) Tackle
 * 2) Charge and Tackle (Expert Mode Only)
 * 3) Crimtane Probe spawning
 * 4) Glitch-o-Matic 3000 (Inflicts "Glitched" debuff)
 * 5) Clone (Expert Mode Only)
 * 6) Time Stop (Expert Mode Only, only when in "Mechanical Mayhem" state)