Mine is eccentric and hard to get along with but not outright evil.
When we first got married she assumed I would be ironing DHs shirts and turning up his trousers (which she had always done for him). I explained that as we both worked FT he would be learning to do these jobs himself. She also used to remjnd me of his family's birthdays and give me gift lists I passed every reminder on to him.
She put me down as 'one of those crazy feminists' for this behaviour. OTOH she would often brag to her friends about my job and she also thinks I should pay for DH's (many) brothers and sisters (the suggested gifts were pretty expensive). So she likes me working in a good career but I should also be a good housewife apparently.
Can't have it both ways MIL
She very often compares me to SIL who is a 'lovely natural mother' I guess I am artificial?? She would be very sniffy about most aspects of my parenting when DC were young. Carrying in a sling/ Finger food/ not leaving to cry/ having birthday parties at home/ not attending enough baby groups.
'Well I don't know why you bother to do that. In my day... and it never did mine any harm. Of course SIL always..' It used to upset me but as I got older I just ignore and don't care. She has no power and she knows it now. Plus she is not interested in children once they get to school age and can talk back anyhow.
The list of topics we do not discuss is extensive politics, Brexit, racism, alternative medicine, finances, food, weight, her other DC and their partners. From experience I know to avoid these topics or I will say something and there will be a stand up row.
Sometimes she makes hurtful comments and doesn't even appear to realise. I never invite her and my family at the same time as she has insulted most of them in the past so they actively avoid her.
Sometimes I think her heart is in the right place but her tongue lets her down. I know she was genuinely sad about my mum dying recently and she sent nice cards to me and my dad. But when trying to console me she somehow managed to get on to her favourite topic of FIL leaving her for OW (15 years of hearing about this now) and how she was actually worse off than my dad because she was left alone too 🤐. She did not appear to realise there was anything wrong in comparing my mums early death from cancer to her ex (who is alive and well) shagging another woman.
I think in essence my issue with her is that she has zero ability to see anyone else's perspective. Therefore everything is always about her. After many years of her ex and none of her DC submitting to her control she still believes that if only everyone did exactly what she wants the world would be a better place. She never learnt the lesson that the only person's behaviour you can ultimately control is your own and this makes her a very unhappy person to be around as she is always disappointed.