Hi. I?m looking for romance manga preferable girlxboy and the guy is yandere. I also really just want the girl to be a strong-female so no damsel in distress.

Here?s an example: Raise wa Tanin ga Ii
(So something like that?)

Cheese in the Trap has a two-faced/intelligent/yandere male lead.
The female lead is no damsel in distress either.
When the male lead ends up helping her it's always manipulative and behind her back, without her being acceptive or requestive of it.