That's what I mean, I don't want to see him get swept up by his new body and abilities and loose that part of himself, and become just a giant user and abuser in a sense. Given how his life had been going before the change I hope he doesn't become petty and mean towards others just because now he can do so. I'd like to see him err on the more cautious and empathetic side of things. At least that's my hope for it anyway, no one has to agree with me.
It seems to me this is pretty much given. To the point it is objectively doesn't make sense, since the bullied guy harboring deep resentment do not end up being a nice guy when given power. The story is very idealistic and just to use an odd sentiment, innocent. Our gentle giant of a main here is nice to a fault really, driven by a compulsion bestowed upon him of course.
I haven't seen signs that this direction would change. Maaaybe a moment of temptation here and there can happen later but i can hardly imagine that the general tone of the story would change, and thus the mc become a douche with it. He is still the good hearted simple guy at heart he was before whose only fault was that he, like so many in his shoes, refused the responsibility of his own predicament. In reality, i'd say he probably has ADHD but in the game.. he simply lacked the determination to change his life. But he didn't blame the world for it.
Seriously, in this story it's Summer who is the massive asshole of a character and should not be forgotten that she is only this interested because mc's looks and overpowering womanizer aura bestowed upon him. So her actual personality gets sidelined. Her redemption arch, if there will be any, is still waiting to unfold but i have a feeling that the mc's newfound desire to reveal himself to be the step-son/step-bro will bring about that as well.