Until someone post chapter 36 here is a link to another site. https://nvmanga.com/webtoon/i-took-care-of-him-but-he-came-back-obsessed-with-me/chapter-36/
I know some people like this ending, but to me it kinda sucks. Basically it's just everyone has darkness inside of them and sometimes that darkness gains form. I expected more and for it not to feel so confusing. Also they left a trashed blood covered house it's not like it's not going to be traced back to them.











Doesn't being a sharing still take their energy and what about the lifespan differences? Feels like they just wanted to end it.
It actually explained tho. If they are sharing mana through their souls/being soul connected (which they are) they don't suffer damage to their life span and even can live as much as the mage. But if they don't love each other they can't bond their souls.