Before explaining Yunru's decision, let's first clarify a hypothesis:
Starting with Dance of Blood, CN bravely decided to send most of its main forces to the distant Totoya Island to intercept Epsilon's ace card, risking its own national defense vacuum. Although the author does not remember when CN stopped striving for the leadership position of the Comintern since Juggernaut (or temporarily did not regard it as its primary goal), the premise assumption of this article is that CN has regarded Yuri as a threat to CN and is willing to cooperate with Soviet Russia if necessary to jointly eliminate Yuri.
The hypothesis that Dance of Blood is Yunru's SS and only Yunru considers Yuri to be the biggest threat, but CN does not think so, is also unfounded for three reasons: firstly, there are no experimental units in Dance of Blood; Secondly, Yunru does not have enough troops to carry out interception, and its own strength is still lacking; Thirdly, Dance of Blood. All CN units use brown color.
Based on the above assumptions, Yunru should have a better decision when deciding the timing of defection: to prepare two sets of plans for launching or not launching Yuri's Mental Omega Device at the same time.
If the Mental Omega Device is successfully launched, Yunru should make the same decision as now, which is to stay as far away from the Mental Omega Device as possible and use the power of The Paradox Engine to isolate itself from the world; However, the failure of the Allies was not necessarily inevitable. For example, the pagans failed to prevent the weather controller from charging, the Infiltrator did not fully infiltrate The Paradox Engine, resulting in Libra being killed by laser cannons, and the E23 Libra did not arrive at The Tower in time (or was killed by Norio), causing The Tower to be delayed and destroyed by The Paradox Engine. Yunru cannot fully understand these variables, and with Rashidi's description of The Paradox Engine, Yunru must carefully examine the power of The Paradox Engine and prepare for the possibility of the Allies truly destroying The Tower.