Fargo's Mod/Brain of Cthulhu (Eternity Mode)

Eternity Mode Brain of Cthulhu is a pre-hardmode. It is a more powerful version of the Brain of Cthulhu with more attacks and new behavior.

Behavior
Brain of Cthulhu's main behavior focuses on Ichor and illusions.

Phase 1
Brain of Cthulhu is invincible and randomly teleports around the player with several Creepers that have 250 HP following it. Creepers shoot a unique variation of Golden Shower. These Golden Shower shots are initially aimed away from the player before turning around and homing in on the player. After approaching close enough, they stop in place and then accelerate to high speed while curving to hit the player. Their fire rate increases as the number of surviving Creepers decreases.

When all Creepers are dead, Brain of Cthulhu enters phase 2, becoming vulnerable.

Phase 2
Brain of Cthulhu spawns harmless illusions all over the screen that become more opaque as its health decreases. Additionally, it has one invulnerable clone that is able to damage the player; this physical clone cannot teleport, but is only vulnerable to knockback at close range.

Brain of Cthulhu and its four primary clones all have identical icons on the map, preventing players from using the map to identify the real boss.

It periodically inflicts Confused, telegraphed by 4 rings of light that come from the Brain and its main clones, then spawns 4 bursts of accelerating lasers around the player. When Confused is about to wear off, a ring of red light appears around the player. When it completely wears off, Brain of Cthulhu shoots another wave of lasers. This pattern repeats, with different variations in the lasers' position around the player, until the boss is defeated.

Tips

 * Since the fight has much more going on compared to Expert Mode, it is heavily recommended to fight it on the surface with a proper arena for more space to dodge.

Trivia

 * If the Eternity Mode Recolors option is turned on in the Mod Configurations menu, it resembles Hive Mind.