KeyFace

KeyFace, sometimes called The Man with the Keys is the main antagonist of Insidious: The Last Key. He appears as a demon with keys for fingers. He is portrayed by Javier Botet, who also played Tristana Medeiros in the REC film series, Mama in the film of the same name, the Leper, one of the many forms of It, in the 2017 adaptation of IT, The Crooked Man, one of the many forms of the Valak in The Conjuring 2 and it's spin-off, The Nun and Slender Man from the 2018 film of the same name.

History
In the 1950's, KeyFace haunted a young Elise Rainier before fully realising her power. After Elise is sent down to the basement as a punishment by her abusive father, Gerald, KeyFace gets her to unlock the red door to The Further, which kept himself trapped. Elise's mother, Audrey Rainier ventures down to the basement and is strangled by KeyFace who possesed Elise.

In the 1960's, after being freed, KeyFace feeds on the hatred inflicted by Gerald Rainier. Gerald begins kidnapping nurses and locking them in the basment eventually killing them with a cane and hiding their bodies in a ventilation shaft, under the influence of KeyFace.

In the modern era, Ted Garza purchases the Rainier family home which had been abandoned and is haunted by KeyFace to capture and contain more nurses in the basement of the house. Ted, acting as Keyface's puppet is killed by Specs after Elise discovers Ted's current victim.

Melissa, daughter of Elise's brother, Christian, is captured by KeyFace while looking for her father's whistle. KeyFace inserts a Key Finger into Melissa's neck which first silences her screaming and then a another into her chest which 'locks' her spirit in The Further.

Elise while investigating the house after the incident with Melissa is guided by a previous victim from the nurse kidnappings to suitcases in a ventilation shaft which held the remains of the victims. KeyFace is hiding in one of the suitcases and drags Elise into The Further.

KeyFace taunts Elise with Gerald's spirit, who is trapped in The Further as punishment for his abusive nature, allowing her to strike her father just like he did to her during her childhood so he could feed from her hatred but is stopped by Imogen who managed to enter The Further. Imogen gets captured by KeyFace but Elise begs him to take her instead.

In a confrontation between Keyface and Elise, Gerald's spirit gets in front of Elise and his stabbed by Keyface, before turning into dust. Before being completely captured Elise attempts to stab KeyFace with a broken crowbar but fails, instead she finds her brother's old whistle and blows it, summoning the spirit of Elise's mother, Audrey Rainier. She destroys KeyFace by smacking him with a lantern, sending him flying away into the darkness.

Keyface's fate in unknown, though it's possible that he got sent to Hell.