"Ya practice with swords huh?" With the kid grinning like that, it was hard to imagine him doing any kind of fighting, training or not. Did he just say mutagen? The anger that had been sizzling in his gut kinda dissipated during this odd conversation. It was hard to stay mad at the circumstances when someone as sweet seeming as Diarmuid was grinning at him so openly without a trace of fear. In fact, he didn't seem bothered at all that Raphael was a mutant turtle. Kids were...kinda amazing.

"One of our brother's trains with swords. His name's Leonardo." He added, wondering how much Donatello told him. He crossed his arms, tilting his head slightly. "So yer trainin' ta be a hero? A real knight like in what...medieval times?" Raph was no history buff, but he watched TV and movies.