Here is the full list of all 11 The Lattice Grimoire achievements.
Got Ryan's Bad Ending
Got Ryan's Good Ending
Got Grayson's Bad Ending
Got Grayson's Good Ending
Got Blake's Bad Ending
Got Blake's Good Ending
Got Meta's Bad Ending
Got Meta's Good Ending
Got Marcellus' Bad Ending
Found Marcellus' Path
Got a True Ending