Lucario was one of two members of the former King Dedede's king's guard. Sworn to protect him while the battle raged for Hyrule castle Lucario stayed near Dedede, that was until Dedede tasked Lucario with escaping with his daughter. While reluctant to leave Lucario did as he was ordered and left with Zelda. He spent the next 18 years protecting and tranining the young Princess until such time as she is ready to take back her Kingdom. Strict and over protective Lucario is like a father-figure to Zelda, he scolds her if she runs off, but also congratulates her on her accomplishments. Though he never openly says it he is very proud of the Women Zelda as grown up to be. Lucario should sound like he's in his early to mid 30's