Sorry, meant to upvote
It’s a bit of a grey area considering she’s over 200yrs old but I think it’s literally because she’s been raising him for like the last seven years (like a mother) and will be for a while longer I think the main issue is because she’s known him since he was a child if she met him when he was an adult there would be no issues, I’m pretty sure a lot of people myself included picked up this webtoon thinking it would be a nice mother son dynamic with some one older being the ml when they raised him ya know? Not hating just trying to shed some light onto why some people might be feeling this way :)
She isn’t grooming him. She only wants to raise him to become a nice person for his future, she isn’t manipulative and abusive, hell even sexual to him. He also doesn’t see her as a mother, I think he knew his real mother before. She’s a witch and ages differently from humans, the age gap doesn’t matter as long as he is old enough. As he becomes older, he’ll realize what he means to her. What’s the problem with people hating, just drop it. :|