Why must Red Hood, Lunpena, Elaine, and others wait for the appearance of the game protagonist Magician before they can conquer the hall?
Because without the Magician's Sacrificial Arm or Hand of Redemption, killing the demons would be futile.
As long as the demons in the hall were not dealt with by the Magician, even if defeated, they would refresh in a short time or even resurrect on the spot with full health.
Red Hood and the others, being Magicians themselves and judging by the appearance of their left and right hands, had clearly performed countless sacrifices and redemptions on demons before, but now, perhaps due to the game's design, this job could only be done by the protagonist Magician.
Watching the Magician redeem the civilians inside the Patchwork Monster and conjure a Fried Chicken Combo out of thin air for them to eat, the saved Caroline was astounded:
"Can magic now create fried chicken?"