Watchers of the Gate

The Watchers of the Gate are three bosses encountered in The Nameless City. They make their appearance in E3M9: The Dweller In Darkness and are exclusive to that level. They resemble buffed versions of The Experiments and The Guardian. Their boss theme is Keepers of the Gate.

Encounter
Upon entering E3M9, the player must enter an arena in order to prove their worthiness. Several enemy waves will spawn, each containing a different common enemy. After defeating the final wave in the arena, these bosses will appear and the boss fight will commence.

Tactical Analysis
The Watchers spawn with a combined health of 24000, giving them the highest health pool of any boss in the game. They behave identically to their Episode 1 and Episode 2 counterparts, but with significantly increased fire rates. Due to the size of the arena, the Guardian's projectiles do not have much room to travel, causing the floor to become a layer of mortar grenades. As long as the Experiments' fire breath can be dodged, the Guardian will end up accidentally killing both Experiments through infighting. Avoiding the mortar grenades and fireballs can be simplified by intentionally falling off the arena. If the player falls off, they will simply be warped back onto the arena, allowing you to be completely out of harms way when the mortars detonate.

Like all bosses, the Watchers are weak to stronger weapons such as the Riveter, Mortar, and Hunting Rifle. Strafe jumping around the arena is a good strategy for avoiding fire from the Experiments, while the Sword can be useful for deflecting the Guardian's grenades back at it. The main trick to beating the Watchers is to always keep moving and to avoid fire wherever possible.