An Obelisk is a recurring symbol within the Shin Megami Tensei games, commonly of unknown origin.
Shin Megami Tensei III: Nocturne
Shin Megami Tensei IMAGINE
Each of the Obelisks has an Innocent assigned to learning more about it. However, according to Yamamoto the Steel-Willed, the Obelisks have been causing these Innocents to act outside the boundaries of their programming.
The Obelisks take a much more important role later on in the Quest "Lord Of The Flies" where the demon Beelzebub takes the power from them in order to become the lord of the new world. After this his fate in unkown, though it is assumed that the Shadow Chaser has defeated him.
An obelisk is a tall, narrow, four-sided, tapering monument which ends in a pyramid-like shape at the top. Ancient obelisks were often monolithic whereas most modern obelisks are made of individual stones, and can even have interior spaces. The term stele is generally used for other monumental standing inscribed sculpted stones.
Because of the Enlightenment-era association of Egypt with mortuary arts, (and generally with great antiquity), obelisks became associated with timelessness. There are many smaller obelisks or similar forms to be found in European and American cemeteries.