Kellunhelk the Cracked Engineer, is a hidden boss located in the Junk Pit location of Ghost Song. His location is off the beaten path, and the only way you can fight him is if you have either a ship part on you or the Curious Gizmo that you can purchase from Mabac’s shop.
Due to the nature of the fight, I’d recommend coming back with the Curious Gizmo. This fight is a three-phase battle. The first phase, Kellunhelk will ride this giant mechanical skill, tossing smaller skulls that will home onto you and explode. Once you’ve done enough damage, you’ll move into the second phase, which is more of the same, except now Kellunhelk is much faster and now hops around the room. The third phase will begin when you kill him, causing his giant skull to go berserk. It doesn’t toss skull bombs, but it is much faster, and more aggressive.
If you have the Hulking Fist and the Suntouch device, you can make this fight travel. The Hulking Fist will turn your jumping attacks into spinning fists of fury. While the Suntouch will provide a lifesteal ability. You’ll literally be damaging him, and healing at the same time.
Once you’ve beaten him, you’ll be awarded the Berserker Device, which increases melee damage, as well as the Hazard Blade, which is found in the next room after the boss. You’ll also earn “The Cracked Engineer Achievement” if you’re on the PC or Xbox, or “The Cracked Engineer Trophy” on PlayStation.
Be sure to check out our review of Ghost Song.