The final boss is Amanda in Beast form. When facing her, do not go near to the edge, near Amanda while she is fighting, or go into the center of the platform. The easiest way to die is to jump off the edge. When you get Amanda's health down about halfway, the beast will fall to the ground and an image of Amanda will appear on the beast's body. Quickly get in close as possible, then face Amanda and press [Interact]. This brings the beast's damage threshold down. If you do not do it fast enough, the beast will rise and heal to full. You must down the beast four times to win. The beast will start by using a random attack every couple seconds. Every time you down the beast, the chance is increased that it will perform another random attack right after the first. This means that when you have downed Amanda three times, she is likely to attack four times very quickly. The following is a list of her attacks:
Spreading attack She will stick her arms into the ground. After a slight delay, slow, red projectiles will fan out. This is easily avoided by jumping over them. Note: This attack is when the beast is most susceptible to damage.
Upwards blast The beast's fastest attack. It will pound the ground with its arms and a burst of energy will appear beneath Lara. This is the best reason to keep moving.
Melee attack A simple swipe. Stay away from the beast and it will not use this attack.
Homing attack The most common attack. The beast fires a pink homing smoke-like projectile that explodes on contact. This has area of effect. The more accurate the blast, the more damage Lara will take and the farther she will fly.
Shockwave The most devastating attack. It doesn't do significant damage but can fling Lara halfway across the platform. Avoid it at all costs. It acts like the homing attack, but looks bluish. There is a distinct difference in appearance between the two projectiles.