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