Meeting Queen Toriel
In Underswap CYMS, Toriel already knew the human would be able to come to here, after sans and alphys called her that the human is determined to go home and wont be stopping anytime soon she made herself ready for the battle, she knows she cant stop the human, so she accepts her fate on whatever will happen to here.
In her mind, she already makes predictions of what might happen in the future if she wins or loses.
If she wins, she will break the barrier and complete her husbands promise.. which will lead her to even more pain in her heart.
If she loses and chara takes her soul, she will accept her fate and knowing she made her people lose hope, after that, her soul will slowly break and turned to dust because of her lost hope..
if she loses but chara spares her, noone will die, they might be trapped in the underground, but the good thing is that everyone lives and will find a better way to leave the barrier, just like how chara planned to.. however
US CYMS Toriel is still like classic toriel however some of her personalities are slightly swapped or mixed with asgore like her friendliness to other monsters and not isolating herself in her castle.