Chained Spikey(Familiar) = Chained Spikeball(enemy)
Amalgamation(Trinket) = Cursed Globin(Enemy)
Siren's Song(Passive) = The Siren(of course)
Fettered Heart(Passive) = The Visage(Heart)
Papyrus Rags(Passive) = Raglich(Unused Boss)
Swen Bond(Trinket) = The Horny Boys(Boss)
Cursed Dice(Active) = Cursed Penny(Trinket)
Secretion(Passive) = Red Cultist(Enemy)
Revenir(Passive) = Revenant(Enemy)
Cursed Flame(Active) = The Visage(Mask)
Lil' Heretic(Familiar) = The Heretic(Boss)
Reverse of the Tower(Passive) = The Tower? Tarot Card
Mended Knife(Familiar) = Knife Pieces(of course)
Soul Cleaver(Active) = The Clutch(Unused Boss)?
Pentacle(Passive) = The Heretic's summoning intro or Teleporter panels
DO NOT TOUCH(Passive) = Red Pressure Plates
Anathema(Passive) = idk

Originally posted by cadetpirx:

Chained Spikey = Chained Spikeball(enemy)
Amalgamation = Cursed Globin(Enemy)
Siren's Song = The Siren(of course)
Fettered Heart = The Visage(Boss)
Papyrus Rags = Raglich(Unused Boss)
Swen Bond = The Horny Boys(Boss)
Cursed Dice = Curse Icon
Revenir = Revenant(Enemy)

Damn that was quick! here two additions:

Cursed flame: Also the Visage! Based on the mask containing fire. So fettered heart references the heart while cursed flame references the mask!

Lil heretic: i'm sure you knew this one already but just missed it