Here is the full list of all 49 99 Spirits achievements.
Walk a Tranquil Path
For Those Who Reached the End
Index All Tsukumogami
Free the World from Evil Influence
Complete Chapter Eleven
Reach Level 50
Vanquish all Great Monsters that Roam the Land
Reach Level 40
Get to Know the Merchant
Complete Chapter Ten
Get to Know the Monk
Complete Chapter Nine
Save a Damsel in Distress
Pay Your Respects
Complete Chapter Eight
Reach Level 30
Amass a Fortune of 100.000
Vanquish a Great Monster
Complete Chapter Seven
Travel 5000 Steps
Reach Level 20
Complete Chapter Six
"Acquire" a Mystical Item
Complete Chapter Five
Free an Area from Evil Influence
Win 500 in a Single Gamble
Win a Gamble
Find All Stone Statues in a Single Playthrough
Master a Tsukumogami
Maximum Utility, No Nonsense
Complete Chapter Four
Complete Chapter Three
Reach Level 10
Win 100 Battles
Amass a Fortune of 20.000
Sell 50 Items
Identify an Enemy Without Any Hints
Complete Chapter Two
Complete Chapter One
Defeat the First Boss Without Using Items
For Big Eaters
Running Is a Victory
Learn All You Can Before Setting Out
Win a Battle Without Missing a Single Counter
Wake up Dozing Hanabusa
Walk the Path of Asura
Receive the Spirits' Blessing
For Those Who Saw It All
Show Proof of Mastering the Use of Gems