Big Show is the main rival of Bully Demise upon entering the world of WWE 2K14. Big Show seems to hate Bully entirely because of his size and little other reason, and regularly goes out of his way to say that Bully is "tiny" despite little to no height difference. His obsession with size amounts to the majority of his characterization, to the point SuperGreatFriend said that "commenting this match amounts to look at this man, look at how big he is, he's so big" during his first King of the Ring match against Tuba.
Big Show surprisingly saves Bully from Killerman, wanting to fight Bully in the ring himself and to "make the company be about wrestling again". It is revealed in episode 9 that he hates Bully because of Vince Mcmahon's plot line to make Bully the main character and defeat Killerman. He heavily breaks the fourth wall, showing desire to be "the main character". Bully Demise hears Big Show out, but only to stall for time to try to recover from the Killerman attack, far too stupid to really care about any of this. While he goes on to have a very close match against Bully, he ultimately loses.
After his loss, Big Show comes to Bully and Vince and says his hatred of Bully was out of fear of being fired due to Bully's heavy promotion, "stylish shirt", and the fact that he's so big. Vince assures him that this was not the case, and he even seems to settle his differences with Bully. Killerman then shows up and fires his laser at Bully, but Big Show blocks the hit and apparently dies.
It is theorized that this was a contingency plan in case Big Show managed to defeat Bully and would happen regardless of the outcome of the match, which was a very real possibility. It is probable that Big Show was always a victim of fate, and would never become a "main character" regardless of his performance.