The Horsemen Of The Apocalypse

The Horsemen Of The Apocalypse are seven War Mode, Post-Celestial Chaos enemies that act as one boss. They are harder than My Dad and Steveobrine combined, and harder than Earth Lord, despite being only slightly later on the progression list. This is due to how hard the Celestial Chaos is, as by that time the difficulty and weapon damage have risen up a lot. In full, the boss has 25000000 / 50000000 / 75000000 HP. They are also the second final non-event boss in Terraria in Normal Mode, the final non-event boss being The Phantom.

Summoning
The Horsemen Of The Apocalypse can only be spawned with the Oofen Sigil, crafted from 15 Venus Essence, 15 Sun Essence, and 15 Andromeda Essence, all of which can be dropped from enemies in the Celestial Chaos. The player must have also have beaten the Oof Attack, Steveobrine, My Dad, and the Celestial Chaos. If the criteria are not met, "Thou're a cheater! Cheater! Cheater!" will be spammed in the chat until you exit.

Battle
The sky will turn dark immediately upon the battle's initiation. It will be even darker than an eclipse - pitch black, that is. The player's sight is greatly decreased. Torches will not work - the only light will be the Horsemen. On the chat, "Get ready, mortal, for the Greatest Challenge of thy life!" will appear. Two Horsemen will appear at first - Oothanos and Beana.