Believe it or not... I am also asexual, but I am only romantically attracted to women, or at least feminine characters, with little to no exceptions...
To add to this... I really hate males being dominant in a physical way of any kind unless it is consented... In real life I feel the same towards females, however if me as a protagonist, or a real life person were asked that by a female (let's say a yandere) if I am ok with this or now... I would likely weirdly enough agree to it.
For me consent makes it turn romantic and that still is very enjoyable to me. I do like cuteness in a yandere, but only if she is female. In a male yandere I just see an enemy... If the girl accepts them, or whatever partner they choose accepts them... None of my business, but I never would accept that from a dude...
However with a villain, where the love is not necessarily the point... If they make sense, no matter their gender, there is no real reason not to side with them. Yes I might hate their means and wish to correct them, but in the Sith Lords comparison I made before... I would act similar to the way I do as a Sith Inquisitor in The Old Republic game... I side with the insane people, who do have a point, but do not agree with their means and show them it can be done better. However if someone is blind to my arguments... I kill them...
With a yandere the love towards me is "the point" that convinces me, but only if I am able to feel romantic attraction back. If the character is feminine, I am capable of that, as long as I am not expected sexual actions (as I already mentioned I am asexual... Also repulsed by sex so... that is a thing). Male yanderes usually make me disgusted, because I have seen guys who claim to do things in the name of love and act like a male yandere, who are just assholes... No matter what even if a girl accepts that and I leave them alone I would still be disgusted by it...
With a female yandere, if she were interested in me specifically I would be more than willing to be with her, but I wouldn't struggle from the beginning though, so there would be no issue of kidnapping me, killing anyone or any of that... She might mention she is jealous of a girl, so I would invite her to meet with me and her together, to show her I don't mean anything wrong and even if the other girl does... she is no longer any kind of competition...
I get the point of "it's supposed to be terryfying tho" but I personally find it silly... you want to struggle your entire life? Why would you settle for a struggle with a man forever and not attempt to kill him, even if you are about to die, but do it with a female? I would not struggle against a feminine yandere and be willing, while not be romantically attracted to a masculine (except for tomboys, but that should be obvious) character and that is why I would struggle and fight back...
No need to explain yourself to me however. I just have a fantasy for a "monster guardian" kind of dynamic. Where the yandere is like that giant who crushed a city of thousands, but then looks at you in a tiny house smiles with the cutest smile and says "now you are no longer a slave and they will not hunt you at all! I killed them all for me! See? *shows their crushed bodies on her hands and feet* done! now come with me cutie!" and so they lived happily ever after...
It doesn't have to be a yandere, it can be a loving sister, a good Sith Lord who loves his subjects and thus starts wars and rules with an iron fist to protect them, a mother who killed her daughter's bully... Any kind of crazy out of compassion, love and all that is what I love. Which is probably why I don't mind when a step-sister or an actual sister is a yandere... I can live with a crazy sister who loves me! I don't need to have sex with her or marry her obviously!
But sadly most people are not asexual and expect every yandere to either kill everyone, die, or get sexy... However with hurting your loved one... One thing is to hurt someone, be it by accident, or on good intention. Like when a kid wants to put their finger into the electric outlet... slapping their hand is technically hurting them, but they would be dead if you didn't act fast enough! Killing a kid for saying a bad name to their mom is... not something I would ever agree with, even if it was supposedly "out of love" and same goes for a yandere girlfriend/wife/whatever. Hurt me to protect me? I do get that... hurt me out of anger? That is a no-no, but it can be made up for... Kill me? That cannot protect me or be made up for... That will never count for me as acceptable. If it is "done out of love" then it was the kind of love I have to purge out of everyone...
I woke up my inner sith lord again, sorry xD but as you can see I also have my feelings of competition here... Just like you, but for different reasons...
We seem to be very close on the topic of crazy characters in some ways but very far, if not on complete opposites in others xD