Kylo Ren:

When you see the change in his emotions, he melts your heart with the saddest look, he melts your heart with the sad puppy eyes, he is really good at it, and you almost cry yourself when you see him doing it. You found that Kylo's puppy eyes are so cute, that it makes him so unique.

Poe Dameron:

He melts your heart with a half smirk, this is a sign of the comical side of him, or when he does it to someone else, a sign of sarcasm, but, with you, he uses it as a way to make you smile and melt your heart at the same time.

Finn:

His trait that melts your heart is the way he gets anxious, like the time he was to rescue Poe Dameron from the First Order, and of course deserted then bravely.

Luke Skywalker:

He melted your heart with all those cool Force thing he did on his X wing fighter, since he was force sensitive, he was able to destroy the First death star

Han Solo:

The quirk that he has that not only melts your heart, but makes you laugh is the fact of his stubborn comical goofiness, even when he's in a mood, he'd tell you how he made the famous 12 parsec kessel run.

Anakin:

He melts your heart when he does something really cute, petting black pug puppies, they lick him to death as they are so friendly to him and you that the cuteness gets you every time.

Obi-Wan Kenobi:

What a charmer he is, he melts your heart every time he makes a comment on your cooking or appearance. A tear forms in your eye, and as a gentleman, he wipes it away and says you are too beautiful to cry.

General Hux:

Sure he may be a cold hearted person, but he does show you that he has a trait that melts your heart too. It's his cat, who sends you roses when you least expect it, you think that is cute, he's romantic, that's his trait.