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