"You need to stop this desire for genocide!" Toriel snapped at her husband.
The King of the underworld was mad with grief, and though he still loved his wife with all his heart,
losing not one but two of his children at the same time broke his heart in a way he could not control.
Not only was darling Chara revealed to be a dark soul bent on revenge, but when his sweet boy tried to take her to the human world to finally rest in peace, he was murdered like a dog,
he was destroyed and taken away from his parents, turned into nothing but dust.
Asriel... his darling child. He was long gone, and since then, Asgore lived, breathed and existed merely to fulfill his revenge on humanity.
"Never! I will avenge our children's murder, I will declare war on all humanity."
"Not all humans are guilty! You can't steal their souls, keep them in that horrible limbo. Please, understand how wrong the path you've taken is. Return to me"
"No. I cannot. I will open that portal and then every last human will suffer for their sins"
Toriel gave her husband a pained look and shook her head in disappointment.
"Then don't expect me to stay by your side while you destroy everything we hold dear"
And just like that, Toriel turned around and left tears streaming down her cheeks, abandoning the only man she ever truly loved.