So is MC ever gonna get revenge on his grandfather and the rest of the family? Or is his r...

I think it was his Old boss from the first life he's gonna get revenge

His revenge is against other people. His old boss who is an enemy of his now grandfather.

His uncle is also technically an enemy, but not on the level of his old boss. He's just annoyance that he will deal with in time.

Eden is a major enemy though. They killed his sister and dad in this life.

??? Is ur memory distorted or what bro
He never hated his family
He just wants to bring back her mother to the main family whichcan be acquired with golden token. Technically the grandpa did nothing wrong, it was just the result of his mother's choice. Raon knows her mom did was wrong and so does the mom.
The only revenge he wants is to kill the silver haired robert/ex boss.
Why do you want the grandpa's ass beaten?! He's been nothing but a secretly doting grandpa lol! Did you even read the story at all?

It's true that some of his fam like his uncles r assholes but they're not exactly worth getting revenge on like Eden or Robert

Yeah, the only thing mother did “wrong” was marry for love and was forced out of the family and her martial arts destroyed. They were then on the run and the father/husband was killed as a result.
She had to beg to be let back in the family, to somewhat protect her son. They were then mistreated the whole time by everyone.
The only reason the grandfather is “dotting” is because MC is strong otherwise he wouldn’t do shit
In the beginning he hated the family, due to their situation, I’m wondering if he just takes over the whole family, or does he end up ruining it, or any other petty form of revenge. Since his mother is still crippled and mocked/treated like shit (even though she used to be direct line, and one of the strongest at that)

I don't think the grandpa ever hated his mom. Eventhough she ran away from home and crippled herself to get married to the love of her life, he still secretly looked after her behind the scenes. Not judging whether marrying for love was a mistake or not, but in this case, raon himself said she was selfish for doing so. And the mother also realized she should've faced her problems with the family members head on instead of running away her problems. I disagree with what you said regarding the geandpa only favoring him cuz he is talented. Please don't forget that grandpa already cared for Raon even back when he was just born and was very weak due to the curse of bitter frost. He wanted his grandson to at least survive and not die eventho his condition was very bad.
Anyway, I've re-read this manhwa 3x but I don't think revenge on his family would happen, he's just focusing on getting accomplishments that will eventually be rewarded with gold token.