Kdramas with a psycho second male lead

Hello, I am looking for any romance kdrama with a  psycho or evil or obsessed to the point of hurting the main male lead or trying to get the female lead through any means. 

The second lead should hhavehis proper time in drama too. Not just appearing in a few scenes or epiaodes. 

Some such kdramas I have liked: 

MIssing you (Hary Borrison) 

Delightful Girl Chun Hyang (Byun Hak Do)

Tale of Nokdu (Crown Prince) 

thank you!

In addition (these are all kdramas):

• +1 Love in Sadness
• Let me Introduce her
• Save Me
• Save Me 2
• Arthdal Chronicles
• Hello Monster
• Kairos
• Mask
• Mr. Sunshine
• My Mister
• Psychopath Diary
• Suspicious Partner
• Tell me what you saw
• Tale of the nine-tailed
• The Game: Towards Zero
• The Last Empress
• Trap
• Bloody Romance (Chinese)
• The Ghost Bride (Taiwan)

Dinner Mate - second male lead is mentally unstable and gets really obsessive over the female lead