a spinoff of Death Note : Tragedy of Light.
In the poster there's Ryuk in all of his evilness, Mahou Shounen Slytherin-wizard Lawliet(L), and slytherin-wizard Yagami Light wearing a DeathRing(not a DeathNote).
Tragedy of Light is a play in 'Harry Potter & The Methods of Rationality' wizarding world to teach evil pureblood wizard family about zanatos gambit.(quoted from tvtropes)
So yeah, Draco & Lucius Malfoy has to go & watch them ^^
Fanart for a wonderful Harry Potter fanfiction by Less Wrong : Harry Potter & The Methods of Rationality[link]