The Hand of God is made of divine flesh that cannot be penetrated even by The Master Blacksmith's 'bug weapons'.
Zero is constantly trying to create a weapon powerful enough to kill God. and uses the hand as a test for her created weapons.
After her defeat by Han Gun-Jae, Zero tried spreading a curse through his body that would destroy his core and lead to Lucid Adventure's collapse. Roy Han managed to dismember his own arm before the curse spread.
It seems like his dismembered arm eventually fell into Zero's possession.
Notes & Trivia
- The Hand was revealed to be Roy Han's in Episode 108.
- Although Roy Han cut off his left hand, it is his right hand that was shown to have been dismembered and used by Zero.