As with every single one of Edge's 'good' ideas, it hatched from boredom and a certain unwise Ninja running his mouth when he shouldn't. When Zidane loudly proclaimed that he was the best at causing trouble in the league proper, he was met with some catcalls, several insults, and several thrown objects. Most however just shook their heads at the pathetic thief, seeing him reduced to such straits to somehow salvage his pride.
When Edge challenged him to a contest to prove this, he eagerly accepted. To make things 'fair', Edge let Zidane use whatever or whoever he could to cause trouble, in up to four fights. Edge was restricted to one fight and could only cause whatever interference he could cause on his own. No outside help. Just his body and wits against whatever Zidane could cook up. The wise members of the Duelling League locked their doors or travelled to another dimension, in the small holes they wouldn't get sucked in.
----
Zidane's first action made for an impressive start. He agreed to have the judge of the Haschel/Jade fight taken out (That lunkhead Steiner was useful for something!) so he could ref the fight in favor of Jade. In return, the smarmy Necromancer agreed to use his talents in the best possible way to cause chaos in Emelious and Rubicant's fight.
"Worthless. Emo. Pathetic. Do you know how much your family hates you? End it all, you wimp. The universe would be better off without you."
Emotional abuse. Cruel. Brutal. Just the trick to undermine Emelious, who left the arena sobbing, swearing revenge against Zidane and Jade for this. Rubicant was also extremely angry with Zidane, as he wished to win the fight with honor, not resorting to such cruel mental attacks. He swore revenge against the Tantalus thief.
A good start for Zidane. But he was just getting started.