Chapter 18. Nihilanth [Black Mesa]
We find ourselves in a large hall, with a huge boss, Nihilanth, hovering in the center—the leader of six-armed flying monsters. The boss can attack with yellow lasers from his hands, unleashes a red firestorm, and fires slow blue projectiles. You can hide from most of his attacks behind the rocks. You can collect ammo around him, and rooms from Earth will teleport into the arena, containing weapons and first aid kits.
Phase 1. Nihilanth is protected by a force field, so first, we destroy the blue crystals above, left, and right. They have several layers of shields; we can use missiles or the Gluon Cannon. It's best to disable automatic missile guidance, otherwise the boss will redirect them.
Phase 2. We need to detonate the sphere around the boss; it consists of separate segments. We can attack the boss through the broken windows. However, Nihilanth will begin to regenerate health from three yellow crystals emerging from the ground; we need to destroy them.
Phase 3. When the boss runs out of crystals, he'll start spinning, his head will open, and inside you'll see the main yellow crystal. Dodge the waves of fire and shoot at the crystal in his head until it explodes. All that's left is to make a choice , and the game is over.
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