I think that Manscorpion Tark is Black Iron Tarkus
The reason behind this is because he is an experiment of Aldia. I think Aldia found the soul of Tarkus to create this monster now Tark. And reasons why is because he is good at tanking against Najka just like Tarkus against the Iron Golem, Tark is very strong and only comes and helps you once just like Tarkus, and that both of them have extremely similar name Tark and Tarkus.
Tark also has a similar helmet compare to Tarkus
Also Tark's upper body is slightly larger than the regular model of your character. And Tarkus is also slightly larger than your character.This is also my first blog tell me what I should do better, and WHAT DO YOU THINK?