1)Moon lover Scarlet Heart Ryeo
This is like the perfect drama for your description !! Possessive, strong, badass ML that only shows his soft side around the one he loves (obs the FL) , he has a tough life since he's very cold hearted but deep down he's kind!!
2) Healer
This is the second perfect drama for your description !! Strong and badass Ji chang wook !!
3) The untamed
Although this is a china drama and it is bromance, trust me in the part where one of the main only opens up for the other lead!!! One of the lead is only kind to the other lead ! The chemistry is out of this planet !!
4) Love and redemption
This drama is out of the world ! The ML is cold on the outside and so soft for the FL. He’s sooo in love with the FL !Plus he’s strong and powerful ! This is also another China drama but this drama has an interesting plot ! All the side characters are the best ! Chemistry is on point !
I personally also really love these kind of dramas too but its hard to find a perfect one ! Out of ALL the dramas I've watched, these are the ones where both leads don't do dumb stuff and make reasonable decisions. Great plots and chemistry too;))