He was once a lifeless body that was sacrificed by tribes in Honor of Makuta. Before his death his hand was cut off to be placed among other in a strange cultist idol. The rest of him was thrown down the same pit Skull Slicer fell into. Once the shadowy figure known as The Dark Master found him his body was resurrected and rebuilt along with bits and pieces of Slicer which may explain his insanity.
To be honest the moc is a bit bland
The pinching claw is from Skull-scorpio with the bohrok eyes and blades switched and the torso looks a lot like Lewa Uniter’s build
The head seems interesting but could use some work
You do know his claw can break masks, while Kulta the skull grinder at full power could only crack them right? That alone should signal his threat levels