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