Here is the full list of all 42 Shiness: The Lightning Kingdom achievements worth 1,000 gamerscore.
Defeat Kaorys
Finish the game (with NO Game Over)
Unlock all Supports
Finish all secondary quests and all contracts
Master every Combo with every character
Inflict 100 guard breaks
Achieve rank F 10 times
Consume every consumable with Poky (at least once)
Win 100 combats only using magic
Defeat Irys
Trigger 50 traps
Win 50 fights without getting hit by the enemy
Solve the puzzle in the Room of 9 Pillars
Reach level 50 with every character
Discover all of Rosalya’s doors
Reach Adorya station without setting off a single alarm
Help the Sister of Secrets
Acquire the Hunting Shoes
Collect 100,000 Uzu
Spend 100,000 Uzu
Create 10 Recipes
Win 100 combats without using magic
Have Irys decrypt a Lightning Shi
Have Kaorys decrypt a Plant Shi
Break free of Ayron
Have 5 characters in your team
Unlock all Spells
Achieve rank S 100 times
Defeat Mother
Get knocked out 50 times
Beat one of each kind of enemy
Catch one of every wildlife
Acquire an Amos
Capture 50 wildlife
Defeat an enemy using Engagement only
Defeat Meos
Beat a legend with rank S
Kill an enemy with the Hyper attack
Honor a Contract
Drop down to 1 HP
Discover 10 Interest Points
Finish a fight without getting hit