Phase 1
- Shoot 12 rockets into his head to advance to phase 2. Be very careful not to miss your shots, since you only have 15 missiles and no Charge Beam.
Phase 2
- Shoot as many missiles as you can, ideally not missing any of the 15. Once you run out of missiles, shoot the weak spot on his tail to advance to phase 3.
Phase 3
- Slide under Corpius, but don't melee counter him. Instead, shoot two missiles and let him hit you with his tail. After that, you'll be able to fire missiles without him moving his head for roughly 1.5 seconds. Once he goes invisible, track him again and end the fight.
corpius_normal.mp4
A total of 26 missiles is required to kill Corpius after phase 1.