Don't bother, these stories are so generic they dont intend to ever make sense. Its just cheap massproduced shit from shit novels for readers who are just happy to have anything to read at all.
When he was bringing her home with him the first time they were attacked by demon beasts and she died protecting him.
The second time around he went straight for her and left days before the demon beasts were even close to their path.
Now because she didn't die on that day and months had passed since then, the Oracle of the nine ice palace saw her and her inner potential.
yeah but she didn't suffer from this disease that makes her incapable of cultivating, because she was the stronger one that protected the both of them from the demon beasts. she would have been able to cultivate but now she cant all of a sudden. that is the part that makes no sense.
Never claimed she was stronger, just that she died trying to protect him. She probably died before ever realizing why she couldn't cultivate, not that her family ever gave her the resources to cultivate in the first place.
But if she couldnt cultivate she wouldnt have had the power to protect them in the first place. she certainly didnt fight demon beasts with her bare hands or some kinda weapon, she would've fought them with magic energy power stuff that can only be used by those that can cultivate.
It's more like she made herself a meat shield out of blind love. No abilities needed
Okay so at the very beginning of this story the MC said that in his past life, (which was still this same life he's in now but he just time skipped back a few decades to his past), that when he originally went to that household to ask for the pink-haired chick's hand in marriage and got his ass whooped, that this blue-haired chick saved him and protected him for a little while, so why is it that now, back in the same past he had before with just a few slight differences, the blue-haired chick somehow has a mysterious illness that prevents her from cultivated when that wasnt even a thing when he lived this life the first time?
nothing changed aside from his cheat knowledge and super cultivation, so why is this chick so useless in this version of his past when she was kickass enough the first time around to protect him?