You don't owe anyone your time. I suggest Everyone set deal breakers in a partner. Write them down. Write your reasoning. Hold yourself to those standards unless you have a rational reason for changing them. Revisit them with every individual.
"But I love them!"
LOVE IS NOT A RATIONAL REASON.
"But they're so hot!"
LUST IS NOT AT ALL A RATIONAL REASON.
You want a lay, have at it, but if someone is toxic I'd suggest avoiding it. There's probably another hot person who isn't going to consume your soul or compromise your principles.
Folks need to stop acquiring partners with the goal to "rehabilitate" them. That doesn't come from outside, and frankly ain't your job. A Toxic Person is like a drowning man who is thrashing so wildly they'll drag down anyone not professionally equiped to handle their destructive behavior.
Flipside, if you're a person seeking someone to "complete you" you should probably have a professional look you over. Just saying. To make sure you ain't one of those damaged folks looking for something outside of themselves they'll never find.
Just observations Fellow Humans. I've been watching y'all a while and giving it a try myself, so at least I can point to the common pitfalls. Do what you want though, you prove me wrong let me know. I always desire more data.