Beat The Dragon Boss
Know your enemy
Every 5th level the huge Obsidian Dragon circles the arena, breathing volleys of three fireballs. It has hundreds of hit points and its explosions hurt even when they miss you directly — but it has a weakness: its head.
Dodge the fireballs
Fireballs travel slower than bullets, so keep strafing sideways and they will sail past. Never stand still to shoot; move, shoot, move again. Building a wall also works — the wood eats the explosion for you.
Aim for the head
Body shots deal normal damage but headshots on dragons hit for extra. Wait for the moment the dragon banks toward you, put your sniper crosshair on its head, and fire. Three or four clean sniper headshots bring even the boss down.
The safe cycle
Fight it in a rhythm: wall up, wait for the volley to explode, step out, land two shots, step back. Repeat. Handle the small drakes first so you are not dodging fire from three directions at once.