The actual fights didn't sting- hell, all friends fight sometimes, and if it was a fight with weapons rather than messy words, well that suited Axel just fine. The cold, efficient way Saïx ordered him about didn't bother much either, because that was just missions, just organization stuff. No, the deepest cut was knowing that ache in his chest whenever he thought about the way things were before was nothing but a petty illusion. Can you regret without a heart? And if not, then why the hell did it still make him feel like shit?