Don't get him wrong. Ichigo was beyond ecstatic to see Rukia again. Time began once again, and her presence broke the mundane life he was living.
He loved Orihime. He loved Kazui. Don't get him wrong about that, either.
Every time he was reunited with Rukia, however, his life got distorted in all the best ways. He was never prepared for his interactions with her, but it was so easy to slip back into their typical banters. She loved riling him up, and he loved riling her up. She knew which buttons to push and didn't hesitate in doing so. There was never any hesitation with her. It was always so easy with her.
Seeing her, a familiar feeling boiled within him. He hadn't felt it since his encounters with Grimmjow and Aizen — that feeling of powerlessness they both gave him and the need to attack them for making him feel so.
Rukia made him feel weak, especially now, because it would've been so easy to be with her. He would've looked forward to all their fights and all their wins. He would've gotten to watch her sleep at night just before his caught up with him. He would've gotten on his right knee and offered an eternity with her — or, hell, she might've beat him at that because that was the type of person she was. They would've been beside one another for all those rainy days and nights.
He wanted to make her feel weak. He wanted to scream and fight her. He wanted to grab her tiny shoulders and shake some sense into her.
It wasn't too late, was it?
Another feeling, so intensely bittersweet, rose up as he watched her kneel down and talk with his son.