Here is the Blades of Time Achievements guide that you can see below to see what you can do to acquire them.
Blades of Time Achievements List
Too Hot For You 15
Kill Brutal Maul without being frozen by his shockwave.
Brutal Kill 15
Kill 5 enemies at once.
Annihilation Kill 30
Kill 10 enemies at once.
Famous Hunter 15
Kill 1000 enemies in total.
Faster Than You! 15
Use Counterattack 100 times.
Grasshopper 15
Use Dash 30 times without touching the ground.
Curious 15
Find half of the notes.
Collector 30
Find all notes.
Ready To Fight 15
Find all types of equipment.
Unstoppable 15
Win any Outbreak match.
Out of My Way 15
Kill an enemy player in Outbreak match.
Outbreak Hero 30
Kill each Outbreak boss at least once.
Experienced 10
Play 5 Outbreak matches.
I'm Rich 15
Find all the chests in story mode on the Normal difficulty level.
Treasure Hunter 30
Find all the chests in story mode on the Hard difficulty level.
Double Attack 15
Kill 25 heavy enemies using the Time Rewind double attack.
Angry 15
Kill 100 enemies during your Time Rewind Berserk buff.
Rain of Bullets 15
Shoot off Magic Armor from 50 enemies using Time Rewind clones.
Secret Achievements
Gather Chi 15
Get the ability to gather Chi.
Rifle 15
Find the rifle.
Coral Dash 15
Get the ability to dash to corals.
Enemy Dash 15
Get the ability to dash to enemies.
Time Rewind 15
Get the ability to rewind time.
Order Spell 15
Survive Chaos event.
Free to go! 30
Kill Gateguard.
Clear the Jungle 30
Kill Shaman Boss.
Your Fire Is Nothing 15
Kill Shaman Boss without taking damage from his massive fire spell.
Old Temple 15
Reach the Sanctuary.
World of Order 30
Defeat Skyguard Commander.
Big Corpse 90
Defeat Giant Worm.
Sky Islands 90
Leave the Sky Islands.
Brutal Lands 90
Kill the Vicar of Chaos.
Dragon 15
Ayumi gets Dragon form.
Keeper Is Dead 90
Finish game on any difficulty.
Hard Times Are Over 90
Finish game on Hard difficulty.