Boss Rush - Official Calamity Mod Wiki

The Boss Rush is a special event that is activated upon the use of Terminus. Although it can be summoned at any point in the game, it is recommended to be fought after all other bosses are defeated. During the event, every vanilla and Calamity boss spawns sequentially in a predetermined order. The bosses summoned have immensely buffed HP and damage and use modified AI, giving them all similar difficulties despite their usual distance in the game's progression. The Boss Rush can be deactivated at any time by using Terminus again.

Boss Rush - Calamity Mod Wiki

Profaned Soul Crystal - Calamity Mod Wiki

Boss Rush - Calamity Mod Wiki

Signus, Envoy of the Devourer - Official Calamity Mod Wiki

Music - Calamity Mod Wiki

Calamity bosses ranked on how fun they are : r/CalamityMod

Calamity Mod🌳 (@CalamityModTeam) / X

was messing around with boss rush, died to king slime, and then this happened, any idea what might've caused this? : r/CalamityMod

Supreme Calamitas Revengeance in 2 attempts OH GOD. P/s: Cheatsheet is used for building arena : r/CalamityMod

Bosses - Official Calamity Mod Wiki

Bosses - Official Calamity Mod Wiki

Bosses - Official Calamity Mod Wiki

I think this especially applies to the Calamity Mod wiki : r/TerrariaMemes

The Ultimate Boss Rush Weapon

Music Boxes - Official Calamity Mod Wiki