Basically I want a drama where the main lead seduces or uses the female/male lead in order to accomplish their revenge. I don't really have too much examples but something like That Winter, the Wind Blows or Innocent Man are ideal. It also doesn't have to be a K-Drama, it can also be Chinese, Japanese, Taiwanese or even Thai.

Le Jun Kai (2013) taiwan , its abit on the heavy side though includes some abuse. I can't remember the ending but I'm doubtful it's a happy one. The best part about this though, was the chemistry of the two leads. They've worked together in at least 3 projects and their chemistry never fails

A Love To Kill. Korean
Bad Guy and Yongpal fit your description, but be warned that both have very messy scripts. Yongpal starts strong then peters out. In Bad Guy, the seduction part is great fun, the revenge, not so much.
thanks, i'll look them up. since some of them look interesting
Sealed with a Kiss --- He blackmails her into being his mistress because he wants revenge on her father, but ends up falling in love her to the point of obsession.  
@rainruma looks interesting cant believe i havent come across this yet
@5Clivi heard good things about that show but long dramas tend to disappoint as the story goes on. but since it has some of my favorite actors ill definitely give it a chance later on
if you liked innocent man you might like the writing and vibe in kdrama 'Secret'  female lead takes the fall for her beloved's hit and run, and the victim's lover sets out for revenge, he plots against female lead and when she's released from prison vows to make her miserable and fulfill his revenge but as story goes on he begins to fall for her while sourcing out truth of the accident. She ends up owing him a debt so he keeps her close and makes her do his bidding. Bitter sweet but lots of depth. I watched it twice  http://mydramalist.com/7761-secret
@HappySqueak although its not exactly what I'm looking for, I do like it and its pretty similar. Thanks!
 rainruma:
Sealed with a Kiss --- He blackmails her into being his mistress because he wants revenge on her father, but ends up falling in love her to the point of obsession.  

Where did you watch this with subs? 

This thread has been resurrected from the dead ~ so sorry for being obnoxious, but if anyone is interested in more recommendations like the ones top (maybe some passer by creepin in the thread): Prosecutor Princess is another drama that fits the criteria. ok. Bye.

 SecondLeadQueen:

Where did you watch this with subs? 

Sealed with a Kiss,  Viki, about 4 yrs ago, but Viki has since removed a lot of content.

On SWAK's MDL page , there's a DailyMotion link....   Also, a YouTube link of raw vids, subtitles from Subscene.

NOTE:  This is not a typical drama of a cold  jerk w/ a heart of gold , he's worse than the leads listed above.

Here's a better synopsis:  http://jolecole.blogspot.com.eg/2011/11/c-drama-sealed-with-kiss.html?m=1

Behind your Smile- he tries to get close to the daughter of a cruel businesswoman who hurt his family

A Love to Kill - he approaches her as her and makes her fall for him out of revenge for something she didn't (he thinks) she caused 

Innocent Man - he ruined his life for a woman he loved and now he uses another woman to get his revenge.