Amalgam

The Amalgam is the final boss of the survival-horror game The Evil Within. It is a "perfected" version of the Amalgam Alpha, the combination of all the rage and anguish of numerous STEM test subjects fused with the mind of Ruvik.

Appearance
The Amalgam is the final evolution of the Amalgam Alpha. Its shape is somewhat less haphazard, having longer and more powerful limbs with fewer vestigial parts. Unlike the Alpha, the final form of the Amalgam has a head, albeit still misshapen and grotesque. The head has a transparent glass dome through which the creature's brain can be seen. Ruvik himself can be seen embedded in the brain tissue, essentially "piloting" the creature.

Based on its name and the Model Viewer description, the Amalgam could very well be the result of Ruvik assimilating every last creature under his command in an attempt to destroy Sebastian Castellanos. As such, it is incredibly massive in size, towering over much of the surrounding skyscrapers and is nigh-indestructible, capable of taking successive rocket launcher hits to the body without flinching, and concentrated high-caliber machine-gun fire could do little than momentarily inconveniencing it, though the transparent brain case is vulnerable to explosives.

History
The Amalgam is the final boss of The Evil Within, being encountered at the very end of the main plot after Ruvik presumably assimilates the consciousness of Leslie Withers. Immediately after failing to stop Ruvik, the entire building starts shaking violently as if hit by an earthquake, before toppling over and throwing Sebastian out the window. As he falls, Sebastian witnesses the scenery around him crumble before landing on a massive brain, onto which the Amalgam lands and immediately starts attacking him.

As the massive creature approaches, Sebastian sees no chance at directly fighting it and flees through a nearby ruined building, but a claw swipe of the Amalgam hits him out of it and onto the bed of a nearby Humvee. Spotting Ruvik in the creature's head dome, Sebastian mounts the Humvee's machine-gun in an attempt to ward it off, but the shots only serve to annoy the beast, who then tosses both the truck and the detective towards a nearby ruin, which impales him on a metal spike. Badly wounded and bleeding profusely, Sebastian sees Ruvik commanding the behemoth towards him. Unwilling to give up and die, he spots the corpse of the Sadist hanging nearby with a rocket launcher, which he quickly commandeers to fend off the Amalgam. Upon hitting and shattering its head dome, Sebastian manages to gravely wound the beast, prompting it to tear him off the spike and throws him onto the ground in an attempt to devour him whole. Fortunately for Sebastian, Ruvik also happens to be relocating into its mouth, presenting him with a chance to take down the villain for good. He takes the shot as the monster's massive mouth engulfs him, though Ruvik seemingly dies before he does, taking his mount down with him.