ML is a bad person at first, but has a good character development

These fit the bill. 

MLs used to be bullies in each of these (they are remakes):

Boys Over Flowers 
F4 Thailand: Boys Over Flowers 
Meteor Garden 

Husbands changing:

18 Again
Doctor Cha 

ML was uncaring:

Ghost Doctor 
Love Between Fairy and Devil 
Tale of the Nine-Tailed (second ML)
Till the End of the Moon 

There is one more but even the title would be a spoiler:

Mouse 

 emeraldarrows:

The Romance of Tiger and Rose 

Rewriting Destiny 

Twisted Fate of Love

Is Xian Zun Whitewashed Today? 

The Queen of Attack  

Night of Love With You

My Villain Husband 

Affairs of a Drama Queen 

I Want to Live to the Finale 

The Man Ripped From the Sky 

Broken Dimension Love 

and maybe

Mr. Bad 

Love Better Than Immortality

Flower of Evil (ML starts out portrayed as very evil but there's a big twist)

 

Thank you. I will start watching  The Man Ripped From the Sky  Broken Dimension Love