Hellp with completing David and Goliath in the challange room.

[AncientMariner]

To late for you kjdro but I post for others who may look for a solution in future.

The metal barriers that block the side rooms can be climbed. This gives you a place to heal up. If you don't object to a bit of 'camping', jump up onto the top of the barrier and tuck yourself in the corner. The Beast can't get you and you've got a point blank shot at its head