Nack's early history was most likely largely the same as his Mobius Prime counterpart's. The point of divergence was when Knuckles became corrupted by his chaos powers and decided to conquer Mobius.
Nack was later hired by Jani-Ca to find the Sword of Acorns for her, though he charged her greatly for it. He eventually found the sword in Downunda after narrowly avoiding numerous Prelate soldiers. Due to the great danger of the assignment, Nack tripled his expected payment. He upheld his end of bargain and delivered the sword to Jani-Ca at the end of the month. Eventually, Nack joined the countless heroes and villains alike that fell to Knuckles, now having assumed the mantle of Enerjak, and had his Core removed.