Here is the full list of all 25 Buff Knight Advanced achievements.
Collect 10 Artifact
Solve Fairy's Quiz 10 times
Kill 1000 Monsters
Solve Fairy's Quiz 5 times
Kill 500 Monsters
Clear Stage 1
Kill 100 Monsters
Use HP Potion 10 Times with 10% of Full HP
Kill 1 Dragon
Kill 5 Dragons
Kill 10 Dragons
Collect 20 Artifact
Collect 20 Artifact and Upgrade Complete
Enchant 10 times
Enchant 50 times
Enchant 100 times
Complete Last Stage
Complete Last Stage + ?
Air Combo 20 times
Air Combo 50 times
Air Combo 70 times
Solve Fairy's Quiz 15 times
Died 100 times
Get the money 1,000,000,000
Get the money 10,000,000,000