Help

Help me find a manhua, i'm not really sure it was manhua or manhwa.

The MC is an orphan, and the place he live forced him to steal. One day he was stealing a man, turns out that man is an important person, he is related with Alchemy/Magic thingy. He has white hair. The man notice that the MC steal money, and he notice that the MC has some kind of talent, and then he took the MC to his home. The man at first want to kill the MC for his experiments? He was a magician/alchemist afterall. But as time passes the man become emotionally attached to the MC, and wants to make thr MC his diciple(their relationship is like son-father for me). But the man need to go to far place before make up his mind to make the MC his diciple. The MC become sad.

And then one day, he found a fruit, and eat it. It was a legendary fruit i think. And after some days, he found an injured man, that man is called Darkness King or something similiar like that. The MC help him, and beat that man enemies. The man also saw the talents in the MC body. And ask the MC to come with him. The MC decline and says that he is waiting for the white haired man. And the man know the white haired man, and told the MC it's fine. And so, the MC write a letter for the white haired man(the letter is so touching at the point i'm almost crying). And the MC is left with the man he helps.

He living with the man, The man teaching hin swordsmanshio and after some years? The man is being killed his enemies. The MC become mad, and swear to revenge the man.

And his life-goal is:
1. To revenge the man
2. To find the white-haired man
3. To meet the girl when he was still living in a place where he was forced to steal

i read this manhua/manhwa long time ago, it was good. And i'm sorry if this is too long.