When you finally reach Golden Star, the mechanical winged dragon, you will notice that it does not stay in one place long enough to hit it with a sword or shoot it with a bow. There is an easier way to turn this boss into scrap by using the environment around you.
Battle strategy:
Find Marni Spears: Run along the edges of the arena and look for metal pillars with a blue glow. Approach them and press E/F to pull out a spear.
Knock the dragon to the ground: While Golden Star is flying, hold RMB to aim at it and press LMB to throw the spear. Your goal is to fill the stun bar under its health bar.
Keep moving: The dragon will constantly breathe fire. Use Shift to dash and get out of the damage zone. Do not stand still.
Attack at close range: As soon as the dragon falls, run toward its head or other vulnerable parts. Use LMB/RMB for regular attacks, and when the on-screen prompt appears, press the finisher key (usually F) to use Spirit energy for a powerful strike.
Repeat: Spears on the pillars respawn automatically. If the dragon takes off again, grab a new spear and repeat the cycle.
If you have trouble aiming with the mouse, try using the target lock function (usually Tab or pressing the mouse wheel) so the camera always keeps the dragon in the center.