Rui and Ieyasu considered the terms of the battle. Both of them had come to learn much in the past four years or so. However, that did not mean the battle was symmetric.
For one, Rui spent a lot of time mastering assassination techniques. Those techniques were much harder to apply in combat. He didn't know what Ieyasu had accomplished in the past four years, but surely it was more directly relevant to combat than the things Rui had been focusing on.
"Does upgrading techniques count?" Rui asked.
"Hmm..." Master Zeamer considered the question. "Alright, techniques upgraded in the past four years will be allowed."
That made it much more palatable. It meant that Rui could use his upgraded Godspeed technique in addition to the Hypnomatrix. Perhaps the most rational decision would be to inform them that he had focused on assassinations for a good chunk of the past four years, but he decided against it.