Here is the full list of all 39 Nine Parchments trophies - there are 20 bronze, 15 silver, 3 gold and 1 platinum.
Unlock Rudolfus the Feline Warlock character variation
Unlock the Searing Senior Marvek character variation
Unlock the Spring Forest Green Cornelius character variation
Complete the game
Unlock the playable character Nim the Cleaner
Complete Vandalism at the Academy in Hardcore difficulty to unlock the Gilded Nim
Unlock the Burgundy Owl character variation
Unlock the playable character Owl
Unlock the Amethyst Owl character variation
Complete A Robotic Rescue Mission in Hardcore difficulty to unlock the Gilded Owl
Unlock the playable character Rudolfus the Strange
Unlock Rudolfus the Moonstruck character variation
Unlock Gislan the Exchange Student character variation
Unlock a heroic playable character
Complete Advanced Box Magic in Hardcore difficulty to unlock our Gilded Hero
Defeat the Chimera of Rage
Defeat the Reef Serpent
Defeat the Silk Tree Guard
Survive the Glacial Den
Unlock the playable character Marvek the Torrid
Defeat Icebeak the Unkind
Survive the Hogmart Arena
Unlock the Cornflower-Blue Cornelius character variation
Defeat the Treasure Mantis
Unlock Gislan the Verdant Witch character variation
Collect all Trophies
Complete the game in Hardcore difficulty with any variation of Cornelius to unlock the Gilded Cornelius
Unlock the Emberlighter Marvek character variation
Complete the Trial of Fire Quest in Hardcore difficulty to unlock the Gilded Marvek
Complete A Stroll Through Meadows in Hardcore difficulty to unlock the Gilded Gislan
Complete A Midnight Summoning quest in Hardcore difficulty to unlock the Gilded Rudolfus
Unlock the playable character Carabel the Glacial
Unlock Carabel the Rimy character variation
Unlock the Carabel of Eventide character variation
Complete the Trial of Ice Quest in Hardcore difficulty to unlock the Gilded Carabel
Unlock the Boreal Nim character variation
Unlock the November Nim character variation
Unlock Amadeus The Box Magician character variation
Unlock Amadeus The Hero character variation