Entity

The Entity (also known as The Evil) is the final boss of Strife. It is a mysterious creature from outer space. It resembles the Spectres, but it is larger and brown. There is one main entity, presumably the "One God" the Sigil refers to throughout the game. When slain, it splits into three smaller Sub Entities. The main entity can fire all five forms of the Sigil, and the Sub Entities can shoot the first and second forms of the Sigil. Like the Spectres, it can only be harmed by the Sigil.

The Entity is the malignant God mentioned in the storyline of Strife. After a comet hit the Earth, many of the survivors started to hear the voice of a malignant God and started to worship it. The Entity presumably controls all the Spectres as well as The Order. Since there are ancient ruins in the game with carvings the Sigil, and the Ruined Temple is host to a Spectre, it can be surmised that the Entity had visited and influenced this planet long before it's arrival. The Veteran Edition expands on its backstory, revealing that it in fact originated on this world, and was sealed by ancients at the cost of their own lives, suggesting that it was then banished into space and the crash-landing of its spaceship was in fact a return to the world of its origin.

The Entity is found in the last map - the UFO. After the player enters the last room, a green pod in the middle of the room will spawn the Entity after some time passes. After the Entity and its Sub Entities are destroyed, the game ends and you win. If the player is killed by one of the Entities, a cinematic will play where he sees that the Earth is doomed.

The main Entity has 2500 Hit Points, and each of the three Sub Entities has 990 Hit Points, totaling 5470 Hit Points for the entire boss fight.

The door to the Entity's lair cannot be opened until all five pieces of the Sigil are obtained.