[By Shounen Jump rules, fear for the safety of his friends make him (physically) stronger.

Faltering in his steps, Tsuna glances down at Rose. He's glad for any sign of life from her -- because breathing, slow breathing makes for iffy proof of vitality sometimes -- but he'd rather she wake up in her own bed than in his arms, so he quickens his pace a tad.]

He has a sword and a tranquilizer gun?! [Isn't that cheating?!] Haaaa... I definitely don't plan on running into him any time soon. So, wait, he was tough, but you won, right...?