Looking for kdramas where the ml is the fl's boyfriend but he's a psychopath

I'm looking for kdramas where the ml is the fl's boyfriend but he's a psychopath (flower of evil or class of lies kinda). I am open to dramas from other countries too but kdramas are preferred

 AH :

For the MLs in these dramas, "psychopath" probably isn't necessarily the exact right word (sociopath or just a person who is a bit twisted or obsessive in a dark way would generally be more accurate) and they don't necessarily ever call themselves the FL's boyfriend, but they are in a romantic relationship of some kind with the FL at some point in the drama:

• Hello Monster 
• The Smile Has Left Your Eyes 
• Doom at Your Service
• Misty
• Tempted
• Cheese in the Trap
• Moon Lovers: Scarlet Heart Ryeo
• The King's Woman

Ohh okay! Thank you for the information and also thank you for the dramas!

Mouse (2021)

Beautiful Mind? And yeah, like what @AH said above, rather than "psychopathic", it's more like the ML in this particular drama can't feel emotions the way most people do. And it's only later in the drama that they start to have a (romantic) relationship.

 cutearisu:

Kill It (2019)

hopefully it will fit in your description

ty!

 Dejes:

• Love Me If You Dare (C-Drama, due to a trauma (heavy one though) he developed a PTSD and he has (for me) the characteristics of a sociopath with difficulty to understand people's feelings, no empathy etc... He will improve so he isn't a real one (Amazing plot by the way with romance as a second side) 

This is also one I wanted where the ml couldn't understand other people's feelings. Thank you so much

 Veera94:

My heart twinkle twinkle fits your description but it's not entirely focused on the couple and has given equal space to other characters. You can try it if you don't mind that.

I will for sure, thank you!

He Is Psychometric (the SML)

He's definitely not a psychopath, but the ML from City Hunter was raised to be a weapon of revenge and told to never care about anyone.

Also the ML in Moon Lovers: Scarlet Heart Ryeo is not a psychopath, but he's very messed up.

And it's a cdrama, but Better a Lie Than a Truth might fit, too.