Here is the full list of all 22 Flynn: Son of Crimson achievements.
Acquire every skill from Loretta.
Completed all levels, acquired every relic and learned every skill.
Find, collect and sell all 20 relics to Yombal.
Complete the 6 challenge stages.
Defeat Zealock
Defeat Imbra the Shadow Sorceress.
Find Bax in 4 separate locations.
Have a throwable rock bounce on an enemy 5 consecutive times without touching the ground.
Defeat Xellios the Toxic Marksman.
Defeat Rozia for the final time in the Desolate Woods.
Have an enemy frozen, burned and zapped simultaneously.
Quickly skip Bohrin's dialogue.
Defeat a training dummy in Sanctia.
Chain zap 7 enemies with lightning magic.
Defeat Kravios the Aquatic Voltknight.
Using the sword, pogo-bounce on 4 separate enemies without touching the ground.
Perform a full plummet combo with any Crimson weapon.
Defeat Bora the Whirlwind Assassin.
Starting with an uppercut, perform a full aerial combo with any Crimson weapon.
Acquired your first skill.
Find and collect a golden relic.
Set out on an adventure with your beloved friend, Dex.