Randy Reyes is acclaimed as a leader in the theater community, successfully serving as artistic director of Mu Performing Arts since 2013. It was acting that brought Reyes to prominence, though, and while his busy schedule limits the number of onstage roles he can take, he becomes a linchpin of any production he joins. Case in point: The Oldest Boy, the reflective Sarah Ruhl play that provided a long-overdue showcase for Asian American performers at the Jungle Theater. Reyes brought gentle conviction to the role a Tibetan Buddhist whose American wife (Christina Baldwin) is learning to embrace a faith that suddenly presents a profound challenge. Even better was Mu’s own tot, wherein Reyes pulled off the daunting trick of playing a school-age boy seething with hurt and frustration after immigrating to America from the Philippines. It was painful to watch, but impossible to look away from.