You did not break me

-First off, she HAS to kill someone to absorb their energy. There's no almost-drowning here. Even when she gets the drain kiss, it'll just allow her to kill out of water.

-The longer she puts it off, the more physical pain she'll be in. Like the original Little Mermaid by Hans Christian Anderson, she'll start to feel stabbing pains in her feet when she walks.

-She acts more like a mythological siren the hungrier she is. She flirts, she's giggly, she acts coy, and basically does everything she can to lure an unsuspecting victim into a false sense of security. Gets even better when she develops magic singing!

-At her worst she flirts with and gets uncomfortably touchy-feely with everyone, including other monsters. She also gets really flippant about hurting/killing people.

-Of course she's going to hate it and hate herself for having to do it... for a while. Then it'll start to get easier. She stops putting it off as long as she can. She claims it's because she doesn't want to go berserk and hurt more people than she has to, but really it's because it's just... not... that... hard... anymore.

-Once she starts feeling numb she'll try to do something "positive" about to make herself feel less worse about it, i.e. offering her kills to monsters who need to eat flesh, offering to take a soul-sucked victim off another monster's hand, anything to make someone else's experience more tolerable. She's sparing someone else from doing this, that makes it okay, right?

-thisisfine.png

-It works but not forever, eventually she'll start to resent monsters who can feed without actually killing someone.

-tl;dr downward spiral of hate and self-loathing!