
I really really REALLY WISH that no. 2 survived somehow !! Pleease

You have to...
Okay, let's say, he didn't die(it would be a possibility since we didn't see him actually die) but how could he survived when he was hurt and what does him returning brings to our MC and to the story? Nothing, that would just make his "death" meaningless and his sacrifice too; and MC did assume he's dead, it would be more "entertaining" if he's still dead when she finds the prince.

Ok but then let's said he did survived.... like you said we didnt see him "die" and he is after all an skill ninja...shinobi? He could have escaped somehow and for what he said at the end that if he was to be reborn he wanted to served our MC ,and him surviving could possibly mean like a reincarnation for him ,so he would go find our MC, because let's not forget that theres still the annoying prince that still wants to make her his... and now the father as well... I know she can defend her self but just knowing that she has a devoted person with her would be great...

I can't remember if they mation this before but in ch.5 page 27 Nagi's mom calls Rio's mom sister... so Nagi and Rio are cousins?

It’s technically incest generation by generation for hundreds of years. I have to wonder when it became the norm. Instead of marrying outside which probably only happened the once when the two families were probably first paired all those hundred years back. Seeing as it’s only a gene pool of two families for hundreds of years it’s worse then cousins they share the exact genes so it’s more like siblings because of the lack of variety.
I don't have a cat but I'm still CRYING