When Ben reaches out his hand and asks Rey to rule with him, she sees a path to a better future. One where she can help the Resistance, end the war, and save Ben Solo. She knows what she needs to do, even though it frightens her. Rey takes his hand.

He couldn't breathe. He couldn't think about anything but the colors and the scared girl in front of him—not just any girl, he realized, his soulmate. A nobody, a scavenger from Jakku was his soul mate. It took one clear look at Rey for the colors to appear. Colors were for Jedi. Colors were for the weak.

The Dark Side of the Force was a pathway to many abilities some considered to be unnatural. And that's exactly what Rey needed. Rey won't let the Force take Ben from her so easily. (TROS Fix-It in two parts)

That was when Luke realized that Han didn't know that Darth Vader was their father. Leia hadn't told him, and judging by how quickly she lied, Luke guessed that she wasn't planning on telling him the truth any time soon.

He had to break. I needed him to break.