She invited her blood be drawn when the monster was getting beaten up. That thing probably never had any compassion given to it, so even such a small act could warrant saving her life.

I hate but also love this cliffhanger. I haven't wanted to see the next episode of an isekai so bad in years.

What this show does well is how it takes its time building up instead of rushing through pay offs. Any other isekai (other than slow-ass Overlord) would've finished this princess arc in 1 episode. We get three.