Here is the full list of all 21 Ys SEVEN achievements.
Complete the game on any difficulty.
Complete the game on Nightmare difficulty.
Obtain all other achievements.
Raise all of any one character's skills to max level.
Synthesize all Dragon Stone weapons.
Synthesize each Spirit Elixir at least once.
Unlock all bestiary entries for all non-boss, non-titano foes.
Conquer the Moon Dragon, Ze-Kalion.
Buy every item from the Zanzibar Firm.
Learn every skill.
Conquer the Sea Dragon, O-Balon.
Conquer the Flame Dragon, Angue-Barl.
Conquer the Wind Dragon, Mu-Anti.
Defeat all titanos.
Find all the missing pikkards.
Conquer the Earth Dragon, Rada-Manj.
Survive against a beast intended specifically to kill you.
Defeat Geis in one-on-one combat.
Escort Tia back to Altago City completely unscathed, and without using any healing items.
Die by walking over thorns.
Die by drowning.