Malayalam actor Prithviraj Sukumaran is all set to make his directorial debut with Mohanlal-starrer "Lucifer"."'Lucifer', starring The Lalettan, written by Murali Gopy, produced by Aashirvad Cinemas will be my directorial debut," Prithviraj posted on his Twitter page on Thursday.Having starred in nearly 100 films, including Bollywood projects such as "Aiyaa" and "Aurangzeb", Prithviraj has been planning to don the director's hat for quite some while now."I soon plan to venture into direction. It gives me a different kind of creative high," Prithviraj had told IANS in an earlier interview.Prithviraj's latest Malayalam film "Oozham" is currently running in cinemas.