Well technically it still makes sense. She’s still saving them indirectly. It must be remembered that the author is constantly naming SYX as the Demon Lord and refers to her as a devil. She’s no hero who selflessly helps others as the word generally refers too. Contrary to what other commentators have said, SYX is always looking for benefits for herself in regards to strangers it is only when she is shown constant genuine affection that she moves to look for benefits for both sides.

That a weird fetish

But not the weirdest.

But also smarter than young master She paid attention to the conversation unlike the young master If they both are dead then the demons will have no slave to eat.... Read more

Though they will still die sooner or later