Here is the full list of all 21 The Tenth Line achievements.
Complete Chapter 1.
Carry out a super attack with a party member.
Call an assist character to attack.
Win a match of Quad Pro Quo.
Win a battle.
Deal 20,000 total damage in one Attack Phase.
Conquer the Champion's Gnaw.
Complete the quest Cold Comfort.
Complete the quest Reeking Rematch.
Complete the quest The Truth.
Launch a foe in the world with an attack.
Reach a 3-digit value in all four stats on any one character.
Deal 1 million total damage.
Collect every Quad Pro Quo card.
Throw 1000 knives in battle as Rik.
Complete Chapter 2.
Complete Chapter 3.
Complete Chapter 4.
Complete Chapter 5.
Complete a Treasure Hunt quest.
Recruit every dracon assist character.