Chimera was the weapon used by Elizabeth Niemand at the top of the TerraNova Incorporated HQ. It was responsible for also the blackouts.
Appearance
The weapon is supposed to be a dragon but some call it more like a snake.
Gameplay
Niemand will fly around in her mech dragon and will shoot explosives at you. You can't attack her when she's flying around the building so avoid her attacks during this time. Eventually, she'll travel over the building and above your head; when she does this you can attack her by targeting the segments of the dragon. While she's flying around, kill the smaller enemies that spawn to keep your health up. When you reduce her health to below half, she'll shoot this wave of green fire at you. Jump over it to avoid taking damage. Destroy the mech dragon to defeat her.
Defeat
In the ending cutscene, Elizabeth's robo-dragon is defeated and starts to malfunction. Elizabeth Niemand is still determined in staying alive for her assignments and that she shouts that she will live for eternity before she is burned to death. This happens before her robo dragon explodes resulting in the TerraNova HQ's top section to collapse after the Chimera explosion creates a series of explosions and a series of flames on the top floors of the building.