Come on guys. There is nothing similar between the Diablo Butcher and the other character. The face looks nothing like it. On the sculpted miniature he wears a mask and has few, longer sharper fangs, as the Butcher has many, small, sharp teeth. The Butcher also has those two, large fangs that shoot out of the mouth that the sculpted figure doesn't have. The horns are nothing alike. The overall costume design is very different. The sculpted figure has this loingcloth whereas the Butcher has a leather apron. The sculpted also has several armour plates for protection, which the Butcher is lacking. The weapon is rather different, too. The Butcher has his boneaxe, while the sculpted has a completely different design to it. The hook? Yea, a bit similar but still not a copy.
While I don't deny that there are inspiration and influences from Diablo, it is so far away from violating any IP that I'm confident in saying that hell has to freeze before this sculpt would be stopped.