Lumian couldn't grasp the meaning of the illusory river he saw or sensed. All he could surmise was that it symbolized fate. Guided by Fallen Mercury's instincts, he lifted the blade's tip and aimed it at a mercury symbol within the river.
As soon as he made contact with the mercury river, a series of scenes flashed through Lumian's mind: Noodle Man performing an enigmatic sacrificial dance; Noodle Man cowering before the black thorn symbol and prostrating itself; Noodle Man gathering the scattered flesh and blood throughout the dream ruins to satiate its hunger; Noodle Man attempting to approach the 'city wall' circle, but retreating each time as if afraid of something; Noodle Man's head severed by an axe…
Is this its entire existence since the loop began? Lumian realized this as he tried to stab the tip of Fallen Mercury at the mercury symbol representing Noodle Man's demise—the end of the illusory river.