[Nightmare Gambling Game]
This gambling game, actively initiated by Catherine, was joined by Yi Chen for two reasons, both overt and covert.
On the surface,
Yi Chen had learned that meat tainted with the nightmare substance had already flooded the market and was consumed by a large number of gentlemen, with at least 50% of Zion's populace suffering from "thought implantation."
If Catherine were to be pushed into a corner, she would need but a snap of her fingers, and Zion would plunge into chaos overnight, the whole city echoing with sinister laughter as gentlemen who failed to transcend their limits would cause mayhem with smiles on their faces.
To preserve Zion and the brains and lives of every citizen,
Yi Chen had but one option—to engage Catherine in the game,
Should he win, according to the "Soul Contract" the two had signed, Catherine would withdraw the thoughts from everyone's brains, clear all nightmare influences from Zion, and completely evacuate.