Here is the full list of all 51 The Legend of Heroes: Sen no Kiseki II KAI -The Erebonian Civil War- achievements.
Earned all trophies.
Achieved student rank A0.
Received the Grand Cordon of the Order of the Phoenix Wings from Emperor Eugent III.
Completed all 39 quests.
Completely filled the monster guide (excluding EX sections).
Obtained all 22 recipes.
Caught all 24 varieties of fish.
Completed all of the character profiles in the notebook.
Completely filled the book section of the notebook (excluding books only available in NG+).
Opened every chest between the Prologue and the Finale.
Gathered all 31 varieties of master quartz.
Completed the game on nightmare difficulty.
Completed the game on hard or nightmare difficulty.
Acquired over a million mira.
Raised a master quartz to level 5.
Acquired the strongest weapon for any character.
Won 100 battles.
Won 600 battles.
Initiated 300 advantage encounters (including double and triple advantage).
Used 100 S-Breaks in battle.
Canceled enemy arts and crafts 100 times.
Won a battle with a tactical bonus of x3.0 or greater.
Defeated 8 enemies at once.
Raised any two characters to Link Level 7.
Used over 500 follow-up attacks in battle.
Used Rush in battle 100 times.
Used Burst in battle 50 times.
Used Overdrive in battle 100 times.
Slayed Isra-Zamiel in Glacia Shrine.
Read the decoded Black Records and had an encounter you'll never forget.
Earned an S rank during part of any chapter.
Forged a strong bond with Alisa.
Forged a strong bond with Elliot.
Forged a strong bond with Laura.
Forged a strong bond with Machias.
Forged a strong bond with Emma.
Forged a strong bond with Jusis.
Forged a strong bond with Fie.
Forged a strong bond with Gaius.
Forged a strong bond with Millium.
Forged a strong bond with Sara.
Forged a strong bond with Towa.
Forged a strong bond with Alfin.
Woke up in the Eisengard Range.
Completed the Prologue.
Completed Act 1.
Completed the Intermission.
Completed Act 2.
Completed the Finale.
Completed the Divertissement.
Completed the Epilogue.