g-iacinto:

“Oh, but you don’t understand, Tsunayoshi-kun!” he lilted cheerfully, grabbing Tsuna’s hands in his own. “You see, these very hands are the ones that murdered a man who would be me. These hands are stained in blood that could flow through my veins.” His tone dropped. “But me? My hands are clean. Just touching you is dirtying me.” He held on anyway.

Tsuna nodded, grasping the hands, "That’s true,”, his face also turned a little dark, a face he’d rarely show anyone, “, and I’d love to dirty them even more if you so much as hint at being the man you were in that future.”

No, he doesn’t expect Byakuran to fully change, but if he hints at being capable of hurting his friends once more, he is ready at any moment to put his foot down.