Complete Monster: The Entity is the ultimate evil of the series. The former Guardian of Hope before being banished to the Underworld because of wrongdoings and corruption, the Entity stole the six medallions that kept balance between the realms and used them to create three loyal servants that'd help him in his harvest of souls—seemingly having a preference for the young. During one of his harvests, the Entity gave the Six to a young girl named Isabelle, leading to her death and transformation. Years later, the Entity tormented a pregnant woman named Faith in her dreams and became obsessed with the latter's daughter—Esther—due to the latter's pure soul, and attempted to have her join him by psychologically breaking her down, even going as far as literally dragging everyone else in Esther's orphanage off to Hell. After being apparently defeated for good, the Entity returns years later to torment an elderly Esther, and has her give one of his servants—Mr. Hopp—to her own granddaughter Ruby before trapping Esther's soul in the Underworld. After Mr. Hopp fails to kill Ruby, the Entity has Ruby taken into the Underworld, where he attempts to have both her and Esther killed by his servants, and later manipulates Ruby into turning against her grandmother, only to attack the poor girl when she betrays him in the third game's Golden Ending.
Hilarious in Hindsight: The series is partly inspired by Lasagna Boy with its stealth-based gameplay and corridor-looking level layout. So when the final release of that game leans more to action and platforming as it caps off with Jon gaining an 11th-Hour Superpower to fight the Dark Lord in the endgame, guess how the third installment for this game and its endgame play out.
Moral Event Horizon: The Entity crossed it before the events of every game by stealing the Six (which kept the balance between realms) and harvesting countless souls (especially those of the young).
