Roberson transferred after two years with UConn.
Parsons played for the Nittany Lions in 2018 and 2019.
Fashanu will play for four years, earning $20,510,710 with a fifth-year option.
McClain's stop with the Sun Devils will be the third of his college career.
Mack reportedly entered the portal on Thursday, May 2.
Henderson became the 13th player to join Penn State's Class of 2025.